staging: vchiq_arm: use __func__ to get function name in debug message

Avoid hardcoded function name using "%s", __func__. This prevents
potential naming conflict if the function is eventually renamed.

Reported by checkpatch.pl
Signed-off-by: Gaston Gonzalez <gascoar@gmail.com>
Link: https://lore.kernel.org/r/20210919215914.539805-8-gascoar@gmail.comSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/vc04_services/interface/vchiq_arm/vchiq_arm.c

@@ -1025,7 +1025,7 @@ service_callback(enum vchiq_reason reason, struct vchiq_header *header,
 			spin_unlock(&msg_queue_spinlock);
 			DEBUG_TRACE(SERVICE_CALLBACK_LINE);
 			DEBUG_COUNT(MSG_QUEUE_FULL_COUNT);
-			vchiq_log_trace(vchiq_arm_log_level, "service_callback - msg queue full");
+			vchiq_log_trace(vchiq_arm_log_level, "%s - msg queue full", __func__);
 			/*
 			 * If there is no MESSAGE_AVAILABLE in the completion
 			 * queue, add one