Fix compiler warnings: sketch/Marlin.h:366:35: warning: large integer implicitly truncated to unsigned type [-Woverflow]

 #define PRINT_TIME_REMAINING_INIT 0xffffffff
sketch/Marlin_main.cpp:8814:21: note: in expansion of macro 'PRINT_TIME_REMAINING_INIT'
  uint16_t print_t = PRINT_TIME_REMAINING_INIT;
sketch/Marlin_main.cpp:8817:15: warning: comparison is always true due to limited range of data type [-Wtype-limits]
  if ((print_t != PRINT_TIME_REMAINING_INIT) && (feedmultiply != 0)) print_t = 100 * print_t / feedmultiply;

Firmware/Marlin.h

@@ -363,7 +363,7 @@ extern uint8_t print_percent_done_normal;
 extern uint32_t print_time_remaining_normal;
 extern uint8_t print_percent_done_silent;
 extern uint32_t print_time_remaining_silent;
-#define PRINT_TIME_REMAINING_INIT 0xffffffff
+#define PRINT_TIME_REMAINING_INIT 0xffff
 #define PRINT_PERCENT_DONE_INIT   0xff
 #define PRINTER_ACTIVE (IS_SD_PRINTING || is_usb_printing || isPrintPaused || (custom_message_type == 4) || saved_printing || (lcd_commands_type == LCD_COMMAND_V2_CAL) || card.paused || mmu_print_saved)