Use unsigned for channel counts

src/drivers/drv_pwm_output.h

@@ -99,7 +99,7 @@ typedef uint16_t	servo_position_t;
 struct pwm_output_values {
 	/** desired pulse widths for each of the supported channels */
 	servo_position_t	values[PWM_OUTPUT_MAX_CHANNELS];
-	int			channel_count;
+	unsigned			channel_count;
 };
 
 /*

src/drivers/hil/hil.cpp

@@ -404,7 +404,7 @@ HIL::task_main()
 				for (unsigned i = 0; i < num_outputs; i++) {
 
 					/* last resort: catch NaN, INF and out-of-band errors */
-					if (i < (unsigned)outputs.noutputs &&
+					if (i < outputs.noutputs &&
 						isfinite(outputs.output[i]) &&
 						outputs.output[i] >= -1.0f &&
 						outputs.output[i] <= 1.0f) {

src/modules/uORB/topics/actuator_outputs.h

@@ -60,7 +60,7 @@
 struct actuator_outputs_s {
 	uint64_t timestamp;				/**< output timestamp in us since system boot */
 	float	output[NUM_ACTUATOR_OUTPUTS];		/**< output data, in natural output units */
-	int noutputs;					/**< valid outputs */
+	unsigned noutputs;					/**< valid outputs */
 };
 
 /**