vfs: fix dentry leak in simple_fill_super()

put dentry if inode allocation failed, d_genocide() cannot release it

Signed-off-by: Konstantin Khlebnikov <khlebnikov@openvz.org>
Signed-off-by: Christoph Hellwig <hch@lst.de>
diff --git a/fs/libfs.c b/fs/libfs.c
index c18e9a1..a2c0029 100644
--- a/fs/libfs.c
+++ b/fs/libfs.c
@@ -510,8 +510,10 @@
 		if (!dentry)
 			goto out;
 		inode = new_inode(s);
-		if (!inode)
+		if (!inode) {
+			dput(dentry);
 			goto out;
+		}
 		inode->i_mode = S_IFREG | files->mode;
 		inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
 		inode->i_fop = files->ops;