uavcan: esc: init msg to avoid publishing random values (PX4#25656)

(cherry picked from commit 2574e03)

Author: dakejahl

src/drivers/uavcan/actuators/esc.cpp

@@ -84,11 +84,7 @@ UavcanEscController::update_outputs(bool stop_motors, uint16_t outputs[MAX_ACTUA
 
 	_prev_cmd_pub = timestamp;
 
-	/*
-	 * Fill the command message
-	 * If unarmed, we publish an empty message anyway
-	 */
-	uavcan::equipment::esc::RawCommand msg;
+	uavcan::equipment::esc::RawCommand msg = {};
 
 	for (unsigned i = 0; i < num_outputs; i++) {
 		if (stop_motors || outputs[i] == DISARMED_OUTPUT_VALUE) {