sunrpc/cache: fix module refcnt leak in a failure path

commit a5990ea1 upstream.

Don't forget to release the module refcnt if seq_open() returns failure.
Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
Cc: J. Bruce Fields <bfields@fieldses.org>
Cc: Neil Brown <neilb@suse.de>
Cc: Trond Myklebust <Trond.Myklebust@netapp.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
Cc: maximilian attems <max@stro.at>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

net/sunrpc/cache.c

@@ -1234,8 +1234,10 @@ static int content_open(struct inode *inode, struct file *file,
 	if (!cd || !try_module_get(cd->owner))
 		return -EACCES;
 	han = __seq_open_private(file, &cache_content_op, sizeof(*han));
-	if (han == NULL)
+	if (han == NULL) {
+		module_put(cd->owner);
 		return -ENOMEM;
+	}
 
 	han->cd = cd;
 	return 0;