AP_MotorsMulticopter: formatting fixes

libraries/AP_Motors/AP_MotorsMulticopter.cpp

@@ -207,7 +207,7 @@ float AP_MotorsMulticopter::apply_thrust_curve_and_volt_scaling(float thrust) co
 {
     float throttle_ratio = thrust;
     // apply thrust curve - domain 0.0 to 1.0, range 0.0 to 1.0
-    if (_thrust_curve_expo > 0.0f){
+    if (_thrust_curve_expo > 0.0f && !is_zero(_batt_voltage_filt.get())){
         throttle_ratio = ((_thrust_curve_expo-1.0f) + safe_sqrt((1.0f-_thrust_curve_expo)*(1.0f-_thrust_curve_expo) + 4.0f*_thrust_curve_expo*_lift_max*thrust))/(2.0f*_thrust_curve_expo*_batt_voltage_filt.get());
     }
 
@@ -350,7 +350,7 @@ void AP_MotorsMulticopter::output_logic()
 
         case SPIN_WHEN_ARMED: {
             // Motors should be stationary or at spin when armed.
-            // Servoes should be moving to correct the current attitude.
+            // Servos should be moving to correct the current attitude.
 
             // set limits flags
             limit.roll_pitch = true;