[media] lirc_dev: simplify if statement in lirc_add_to_buf

The whole function is inside an 'if' statement
("if (ir->d.add_to_buf)").

Check the opposite of that statement at the beginning and exit,
this way we can have one level less of indentation.
Signed-off-by: Andi Shyti <andi.shyti@samsung.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>

drivers/media/rc/lirc_dev.c

@@ -97,10 +97,12 @@ static void lirc_irctl_cleanup(struct irctl *ir)
  */
 static int lirc_add_to_buf(struct irctl *ir)
 {
-	if (ir->d.add_to_buf) {
-		int res = -ENODATA;
+	int res;
 	int got_data = -1;
 
+	if (!ir->d.add_to_buf)
+		return 0;
+
 	/*
 	 * service the device as long as it is returning
 	 * data and we have space
@@ -114,9 +116,6 @@ static int lirc_add_to_buf(struct irctl *ir)
 		kthread_stop(ir->task);
 
 	return got_data ? 0 : res;
-	}
-
-	return 0;
 }
 
 /* main function of the polling thread