Fix z feedrate value when doing mesh bed leveling. probe feedrate uses XY_PROBE_SPEED

Marlin/Marlin_main.cpp

 
   inline void _mbl_goto_xy(float x, float y) {
     float old_feedrate_mm_s = feedrate_mm_s;
-    feedrate_mm_s = homing_feedrate_mm_s[X_AXIS];
+    feedrate_mm_s = homing_feedrate_mm_s[Z_AXIS];
 
     current_position[Z_AXIS] = MESH_HOME_SEARCH_Z
       #if Z_CLEARANCE_BETWEEN_PROBES > Z_HOMING_HEIGHT
     ;
     line_to_current_position();
 
+    feedrate_mm_s = MMM_TO_MMS(XY_PROBE_SPEED);
     current_position[X_AXIS] = LOGICAL_X_POSITION(x);
     current_position[Y_AXIS] = LOGICAL_Y_POSITION(y);
     line_to_current_position();
 
     #if Z_CLEARANCE_BETWEEN_PROBES > 0 || Z_HOMING_HEIGHT > 0
+      feedrate_mm_s = homing_feedrate_mm_s[Z_AXIS];
       current_position[Z_AXIS] = LOGICAL_Z_POSITION(MESH_HOME_SEARCH_Z);
       line_to_current_position();
     #endif

Marlin/ultralcd.cpp

       line_to_current(Z_AXIS);
       current_position[X_AXIS] = LOGICAL_X_POSITION(x);
       current_position[Y_AXIS] = LOGICAL_Y_POSITION(y);
-      line_to_current(manual_feedrate_mm_m[X_AXIS] <= manual_feedrate_mm_m[Y_AXIS] ? X_AXIS : Y_AXIS);
+      planner.buffer_line_kinematic(current_position, MMM_TO_MMS(XY_PROBE_SPEED), active_extruder);
       #if Z_HOMING_HEIGHT > 0
         current_position[Z_AXIS] = LOGICAL_Z_POSITION(MESH_HOME_SEARCH_Z);
         line_to_current(Z_AXIS);