block_device_operations->release() should return void

The value passed is 0 in all but "it can never happen" cases (and those
only in a couple of drivers) *and* it would've been lost on the way
out anyway, even if something tried to pass something meaningful.
Just don't bother.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/drivers/md/md.c b/drivers/md/md.c
index 4c74424..6330c72 100644
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -6674,15 +6674,13 @@
 	return err;
 }
 
-static int md_release(struct gendisk *disk, fmode_t mode)
+static void md_release(struct gendisk *disk, fmode_t mode)
 {
  	struct mddev *mddev = disk->private_data;
 
 	BUG_ON(!mddev);
 	atomic_dec(&mddev->openers);
 	mddev_put(mddev);
-
-	return 0;
 }
 
 static int md_media_changed(struct gendisk *disk)