Copter: minor spelling fix

non-functional change

ArduCopter/land_detector.cpp

@@ -63,7 +63,7 @@ void Copter::update_land_detector()
         bool motor_at_lower_limit = motors->limit.throttle_lower && attitude_control->is_throttle_mix_min();
 #endif
 
-        // check that the airframe is not accelerating (not falling or breaking after fast forward flight)
+        // check that the airframe is not accelerating (not falling or braking after fast forward flight)
         bool accel_stationary = (land_accel_ef_filter.get().length() <= LAND_DETECTOR_ACCEL_MAX);
 
         // check that vertical speed is within 1m/s of zero

ArduCopter/mode_drift.cpp

@@ -89,7 +89,7 @@ void Copter::ModeDrift::run()
 
     // If we let go of sticks, bring us to a stop
     if(is_zero(target_pitch)){
-        // .14/ (.03 * 100) = 4.6 seconds till full breaking
+        // .14/ (.03 * 100) = 4.6 seconds till full braking
         breaker += .03f;
         breaker = MIN(breaker, DRIFT_SPEEDGAIN);
         target_pitch = pitch_vel * breaker;