mtd_blktrans_ops->release() should return void

Both existing instances always return 0 and even if they didn't,
the value would be lost on the way out.  Just don't bother...

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/drivers/mtd/mtdblock.c b/drivers/mtd/mtdblock.c
index 6c6d807..2aef5dd 100644
--- a/drivers/mtd/mtdblock.c
+++ b/drivers/mtd/mtdblock.c
@@ -308,7 +308,7 @@
 	return 0;
 }
 
-static int mtdblock_release(struct mtd_blktrans_dev *mbd)
+static void mtdblock_release(struct mtd_blktrans_dev *mbd)
 {
 	struct mtdblk_dev *mtdblk = container_of(mbd, struct mtdblk_dev, mbd);
 
@@ -333,8 +333,6 @@
 	mutex_unlock(&mtdblks_lock);
 
 	pr_debug("ok\n");
-
-	return 0;
 }
 
 static int mtdblock_flush(struct mtd_blktrans_dev *dev)