Copter: add missing fallthrough statements

ArduCopter/mode_althold.cpp

@@ -55,7 +55,7 @@ void ModeAltHold::run()
 
     case AltHold_Landed_Ground_Idle:
         attitude_control->set_yaw_target_to_current_heading();
-        // FALLTHROUGH
+        FALLTHROUGH;
 
     case AltHold_Landed_Pre_Takeoff:
         attitude_control->reset_rate_controller_I_terms();

ArduCopter/mode_flowhold.cpp

@@ -283,7 +283,7 @@ void ModeFlowHold::run()
 
     case AltHold_Landed_Ground_Idle:
         attitude_control->set_yaw_target_to_current_heading();
-        // FALLTHROUGH
+        FALLTHROUGH;
 
     case AltHold_Landed_Pre_Takeoff:
         attitude_control->reset_rate_controller_I_terms();

ArduCopter/mode_loiter.cpp

@@ -151,7 +151,7 @@ void ModeLoiter::run()
 
     case AltHold_Landed_Ground_Idle:
         attitude_control->set_yaw_target_to_current_heading();
-        // FALLTHROUGH
+        FALLTHROUGH;
 
     case AltHold_Landed_Pre_Takeoff:
         attitude_control->reset_rate_controller_I_terms();

ArduCopter/mode_poshold.cpp

@@ -150,7 +150,7 @@ void ModePosHold::run()
         loiter_nav->init_target();
         loiter_nav->update();
         attitude_control->set_yaw_target_to_current_heading();
-        // FALLTHROUGH
+        FALLTHROUGH;
 
     case AltHold_Landed_Pre_Takeoff:
         attitude_control->reset_rate_controller_I_terms();

ArduCopter/mode_sport.cpp

@@ -103,7 +103,7 @@ void ModeSport::run()
 
     case AltHold_Landed_Ground_Idle:
         attitude_control->set_yaw_target_to_current_heading();
-        // FALLTHROUGH
+        FALLTHROUGH;
 
     case AltHold_Landed_Pre_Takeoff:
         attitude_control->reset_rate_controller_I_terms();

ArduCopter/mode_stabilize_heli.cpp

@@ -65,6 +65,7 @@ void ModeStabilize_Heli::run()
         if (!motors->limit.throttle_lower) {
             set_land_complete(false);
         }
+        break;
     case AP_Motors::SpoolState::SPOOLING_UP:
     case AP_Motors::SpoolState::SPOOLING_DOWN:
         // do nothing