Remove uninitialized variables

Firmware/ultralcd.cpp

@@ -6441,13 +6441,12 @@ static bool lcd_selfcheck_axis_sg(char axis) {
 			enable_endstops(false);
 
 			const char *_error_1;
-			const char *_error_2;
 
 			if (axis == X_AXIS) _error_1 = "X";
 			if (axis == Y_AXIS) _error_1 = "Y";
 			if (axis == Z_AXIS) _error_1 = "Z";
 
-			lcd_selftest_error(9, _error_1, _error_2);
+			lcd_selftest_error(9, _error_1, NULL);
 			current_position[axis] = 0;
 			plan_set_position(current_position[X_AXIS], current_position[Y_AXIS], current_position[Z_AXIS], current_position[E_AXIS]);
 			reset_crash_det(axis);
@@ -6460,13 +6459,12 @@ static bool lcd_selfcheck_axis_sg(char axis) {
 		if (abs(measured_axis_length[0] - measured_axis_length[1]) > 1) { //check if difference between first and second measurement is low
 			//loose pulleys
 			const char *_error_1;
-			const char *_error_2;
 
 			if (axis == X_AXIS) _error_1 = "X";
 			if (axis == Y_AXIS) _error_1 = "Y";
 			if (axis == Z_AXIS) _error_1 = "Z";
 
-			lcd_selftest_error(8, _error_1, _error_2);
+			lcd_selftest_error(8, _error_1, NULL);
 			current_position[axis] = 0;
 			plan_set_position(current_position[X_AXIS], current_position[Y_AXIS], current_position[Z_AXIS], current_position[E_AXIS]);
 			reset_crash_det(axis);
@@ -6880,8 +6878,7 @@ static bool lcd_selftest_fsensor() {
 	fsensor_init();
 	if (fsensor_not_responding)
 	{
-		const char *_err;
-		lcd_selftest_error(11, _err, _err);
+		lcd_selftest_error(11, NULL, NULL);
 	}
 	return(!fsensor_not_responding);
 }
@@ -7036,8 +7033,7 @@ static bool lcd_selftest_fan_dialog(int _fan)
 	}
 	if (!_result)
 	{
-		const char *_err;
-		lcd_selftest_error(_errno, _err, _err);
+		lcd_selftest_error(_errno, NULL, NULL);
 	}
 	return _result;
 }