Fix bugs found through compiler warnings

src/modules/commander/commander.cpp

@@ -603,6 +603,7 @@ bool handle_command(struct vehicle_status_s *status, const struct safety_s *safe
 		// XXX TODO
 	}
 
+    return true;
 }
 
 int commander_thread_main(int argc, char *argv[])

src/modules/ekf_att_pos_estimator/estimator.cpp

@@ -1986,7 +1986,7 @@ void AttPosEKF::calcposNED(float (&posNED)[3], double lat, double lon, float hgt
     posNED[2] = -(hgt - hgtRef);
 }
 
-void AttPosEKF::calcLLH(float (&posNED)[3], float lat, float lon, float hgt, float latRef, float lonRef, float hgtRef)
+void AttPosEKF::calcLLH(float posNED[3], float &lat, float &lon, float &hgt, float latRef, float lonRef, float hgtRef)
 {
     lat = latRef + posNED[0] * earthRadiusInv;
     lon = lonRef + posNED[1] * earthRadiusInv / cos(latRef);

src/modules/ekf_att_pos_estimator/estimator.h

@@ -301,7 +301,7 @@ static void calcvelNED(float (&velNED)[3], float gpsCourse, float gpsGndSpd, flo
 
 static void calcposNED(float (&posNED)[3], double lat, double lon, float hgt, double latRef, double lonRef, float hgtRef);
 
-static void calcLLH(float (&posNED)[3], float lat, float lon, float hgt, float latRef, float lonRef, float hgtRef);
+static void calcLLH(float posNED[3], float &lat, float &lon, float &hgt, float latRef, float lonRef, float hgtRef);
 
 static void quat2Tnb(Mat3f &Tnb, const float (&quat)[4]);
 

src/modules/gpio_led/gpio_led.c

@@ -189,7 +189,8 @@ int gpio_led_main(int argc, char *argv[])
 		} else if (!strcmp(argv[1], "stop")) {
 			if (gpio_led_started) {
 				gpio_led_started = false;
-				warnx("stop");
+                // FIXME: Is this correct? changed from warnx
+				errx(0, "stop");
 
 			} else {
 				errx(1, "not running");

src/modules/px4iofirmware/sbus.c

@@ -119,13 +119,19 @@ sbus_init(const char *device)
 bool
 sbus1_output(uint16_t *values, uint16_t num_values)
 {
-	write(sbus_fd, 'A', 1);
+    // FIXME: I assume this was previously NYI?
+    ssize_t cBytes = num_values * sizeof(values[0]);
+	ssize_t cBytesWritten = write(sbus_fd, values, cBytes);
+    return cBytesWritten == cBytes;
 }
 
 bool
 sbus2_output(uint16_t *values, uint16_t num_values)
 {
-	write(sbus_fd, 'B', 1);
+    // FIXME: I assume this was previously NYI?
+    ssize_t cBytes = num_values * sizeof(values[0]);
+	ssize_t cBytesWritten = write(sbus_fd, values, cBytes);
+    return cBytesWritten == cBytes;
 }
 
 bool