Use logic in Z_SAFE_HOMING

Use logic in Z_SAFE_HOMING

From
```
if (home_all_axis || homeZ) {
  if (home_all_axis) {
  ...
  home z
  }
  else if (homeZ) { // Don't need to Home Z twice
  home z
  }
}

```
to
```
if (home_all_axis || homeZ) {
  if (home_all_axis) {
  ...
  }
  home z
}
```

Marlin/Marlin_main.cpp

@@ -3015,36 +3015,30 @@ inline void gcode_G28() {
              */
             current_position[X_AXIS] = destination[X_AXIS];
             current_position[Y_AXIS] = destination[Y_AXIS];
-
-            // Home the Z axis
-            HOMEAXIS(Z);
           }
 
-          else if (homeZ) { // Don't need to Home Z twice
+          // Let's see if X and Y are homed
+          if (axis_unhomed_error(true, true, false)) return;
 
-            // Let's see if X and Y are homed
-            if (axis_unhomed_error(true, true, false)) return;
+          /**
+           * Make sure the Z probe is within the physical limits
+           * NOTE: This doesn't necessarily ensure the Z probe is also
+           * within the bed!
+           */
+          float cpx = current_position[X_AXIS], cpy = current_position[Y_AXIS];
+          if (   cpx >= X_MIN_POS - (X_PROBE_OFFSET_FROM_EXTRUDER)
+              && cpx <= X_MAX_POS - (X_PROBE_OFFSET_FROM_EXTRUDER)
+              && cpy >= Y_MIN_POS - (Y_PROBE_OFFSET_FROM_EXTRUDER)
+              && cpy <= Y_MAX_POS - (Y_PROBE_OFFSET_FROM_EXTRUDER)) {
 
-            /**
-             * Make sure the Z probe is within the physical limits
-             * NOTE: This doesn't necessarily ensure the Z probe is also
-             * within the bed!
-             */
-            float cpx = current_position[X_AXIS], cpy = current_position[Y_AXIS];
-            if (   cpx >= X_MIN_POS - (X_PROBE_OFFSET_FROM_EXTRUDER)
-                && cpx <= X_MAX_POS - (X_PROBE_OFFSET_FROM_EXTRUDER)
-                && cpy >= Y_MIN_POS - (Y_PROBE_OFFSET_FROM_EXTRUDER)
-                && cpy <= Y_MAX_POS - (Y_PROBE_OFFSET_FROM_EXTRUDER)) {
-
-              // Home the Z axis
-              HOMEAXIS(Z);
-            }
-            else {
-              LCD_MESSAGEPGM(MSG_ZPROBE_OUT);
-              SERIAL_ECHO_START;
-              SERIAL_ECHOLNPGM(MSG_ZPROBE_OUT);
-            }
-          } // !home_all_axes && homeZ
+            // Home the Z axis
+            HOMEAXIS(Z);
+          }
+          else {
+            LCD_MESSAGEPGM(MSG_ZPROBE_OUT);
+            SERIAL_ECHO_START;
+            SERIAL_ECHOLNPGM(MSG_ZPROBE_OUT);
+          }
 
           #if ENABLED(DEBUG_LEVELING_FEATURE)
             if (DEBUGGING(LEVELING)) {