Fix for the PR #4023(Add macros to move servos)

・Add missing ')'

Marlin/Marlin_main.cpp

     #if ENABLED(HAS_SERVO_ENDSTOPS)
 
       // Engage Z Servo endstop if enabled
-      if (SERVO_ENDSTOP_EXISTS(Z_AXIS)
+      if (SERVO_ENDSTOP_EXISTS(Z_AXIS))
         DEPLOY_SERVO_ENDSTOP(Z_AXIS);
 
     #elif ENABLED(Z_PROBE_ALLEN_KEY)