Fix SWITCHING_NOZZLE zdiff (#11683)

Marlin/src/module/tool_change.cpp

 
         #endif // !DUAL_X_CARRIAGE
 
-        #if ENABLED(SWITCHING_NOZZLE)
-          // The newly-selected extruder Z is actually at...
-          current_position[Z_AXIS] -= zdiff;
-        #endif
-
         // Tell the planner the new "current position"
         SYNC_PLAN_POSITION_KINEMATIC();