Restore the last E axis position correctly after powerpanic

- Initially restore the last E position from the eeprom in any case, not
  just when using absolute mode (although unnecessary: since it will be
  reset later), fixing a possible unitialized position and crash during
  recovery (thanks to @leptun)
- Remove useless extra calls to put the extruder in relative mode:
  the extruder already starts in relative mode and is later switched to
  absolute.
- Replace incorrect calls to STRINGIFY with sprintf_P
- Retract after pressure has been restored in uvlo_tiny, to be
  consistent with a regular uvlo (remove the bogus double unretract
  as a result).
- Set the real E position prior to the panic *after* the retraction,
  using the now-fixed G92.

Firmware/Marlin_main.cpp

@@ -10778,12 +10778,15 @@ void recover_print(uint8_t automatic) {
 	enquecommand(cmd);
 
 	enquecommand_P(PSTR("M83")); //E axis relative mode
-	//enquecommand_P(PSTR("G1 E5 F120")); //Extrude some filament to stabilize pessure
-    // If not automatically recoreverd (long power loss), extrude extra filament to stabilize 
-    if(automatic == 0){ 
-        enquecommand_P(PSTR("G1 E5 F120")); //Extrude some filament to stabilize pessure 
-    } 
-	enquecommand_P(PSTR("G1 E"  STRINGIFY(-default_retraction)" F480"));
+
+    // If not automatically recoreverd (long power loss)
+    if(automatic == 0){
+        //Extrude some filament to stabilize the pressure
+        enquecommand_P(PSTR("G1 E5 F120"));
+        // Retract to be consistent with a short pause
+        sprintf_P(cmd, PSTR("G1 E%-0.3f F2700"), default_retraction);
+        enquecommand(cmd);
+    }
 
 	printf_P(_N("After waiting for temp:\nCurrent pos X_AXIS:%.3f\nCurrent pos Y_AXIS:%.3f\n"), current_position[X_AXIS], current_position[Y_AXIS]);
 
@@ -10794,7 +10797,6 @@ void recover_print(uint8_t automatic) {
 
 void recover_machine_state_after_power_panic(bool bTiny)
 {
-  char cmd[30];
   // 1) Recover the logical cordinates at the time of the power panic.
   // The logical XY coordinates are needed to recover the machine Z coordinate corrected by the mesh bed leveling.
   current_position[X_AXIS] = eeprom_read_float((float*)(EEPROM_UVLO_CURRENT_POSITION + 0));
@@ -10829,12 +10831,9 @@ void recover_machine_state_after_power_panic(bool bTiny)
     UVLO_Z_AXIS_SHIFT + float((1024 - eeprom_read_word((uint16_t*)(EEPROM_UVLO_Z_MICROSTEPS)) 
     + 7) >> 4) / cs.axis_steps_per_unit[Z_AXIS];
   }
-  if (eeprom_read_byte((uint8_t*)EEPROM_UVLO_E_ABS)) {
-	  current_position[E_AXIS] = eeprom_read_float((float*)(EEPROM_UVLO_CURRENT_POSITION_E));
-	  sprintf_P(cmd, PSTR("G92 E"));
-	  dtostrf(current_position[E_AXIS], 6, 3, cmd + strlen(cmd));
-	  enquecommand(cmd);
-  }
+
+  // Recover last E axis position
+  current_position[E_AXIS] = eeprom_read_float((float*)(EEPROM_UVLO_CURRENT_POSITION_E));
 
   memcpy(destination, current_position, sizeof(destination));
 
@@ -10929,8 +10928,6 @@ void restore_print_from_eeprom() {
 	uint32_t position = eeprom_read_dword((uint32_t*)(EEPROM_FILE_POSITION));
 	SERIAL_ECHOPGM("Position read from eeprom:");
 	MYSERIAL.println(position);	
-  // E axis relative mode.
-	enquecommand_P(PSTR("M83"));
   // Move to the XY print position in logical coordinates, where the print has been killed.
 	strcpy_P(cmd, PSTR("G1 X")); strcat(cmd, ftostr32(eeprom_read_float((float*)(EEPROM_UVLO_CURRENT_POSITION + 0))));
 	strcat_P(cmd, PSTR(" Y"));   strcat(cmd, ftostr32(eeprom_read_float((float*)(EEPROM_UVLO_CURRENT_POSITION + 4))));
@@ -10942,16 +10939,20 @@ void restore_print_from_eeprom() {
 	strcpy_P(cmd, PSTR("G1 Z")); strcat(cmd, ftostr32(eeprom_read_float((float*)(EEPROM_UVLO_CURRENT_POSITION_Z))));
 	enquecommand(cmd);
   // Unretract.
-	enquecommand_P(PSTR("G1 E"  STRINGIFY(2*default_retraction)" F480"));
+    sprintf_P(cmd, PSTR("G1 E%0.3f F2700"), default_retraction);
+    enquecommand(cmd);
+  // Recover final E axis position and mode
+    float pos_e = eeprom_read_float((float*)(EEPROM_UVLO_CURRENT_POSITION_E));
+    sprintf_P(cmd, PSTR("G92 E"));
+    dtostrf(pos_e, 6, 3, cmd + strlen(cmd));
+    enquecommand(cmd);
+    if (eeprom_read_byte((uint8_t*)EEPROM_UVLO_E_ABS))
+        enquecommand_P(PSTR("M82")); //E axis abslute mode
   // Set the feedrates saved at the power panic.
 	sprintf_P(cmd, PSTR("G1 F%d"), feedrate_rec);
 	enquecommand(cmd);
 	sprintf_P(cmd, PSTR("M220 S%d"), feedmultiply_rec);
 	enquecommand(cmd);
-	if (eeprom_read_byte((uint8_t*)EEPROM_UVLO_E_ABS))
-	{
-	  enquecommand_P(PSTR("M82")); //E axis abslute mode
-	}
   // Set the fan speed saved at the power panic.
 	strcpy_P(cmd, PSTR("M106 S"));
 	strcat(cmd, itostr3(int(fan_speed_rec)));