autofs4 - fix dentry leak in autofs4_expire_direct()

There is a missing dput() when returning from autofs4_expire_direct()
when we see that the dentry is already a pending mount.

Signed-off-by: Ian Kent <raven@themaw.net>
Acked-by: David Howells <dhowells@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

fs/autofs4/expire.c

@@ -290,10 +290,8 @@ struct dentry *autofs4_expire_direct(struct super_block *sb,
 	spin_lock(&sbi->fs_lock);
 	ino = autofs4_dentry_ino(root);
 	/* No point expiring a pending mount */
-	if (ino->flags & AUTOFS_INF_PENDING) {
-		spin_unlock(&sbi->fs_lock);
-		return NULL;
-	}
+	if (ino->flags & AUTOFS_INF_PENDING)
+		goto out;
 	if (!autofs4_direct_busy(mnt, root, timeout, do_now)) {
 		struct autofs_info *ino = autofs4_dentry_ino(root);
 		ino->flags |= AUTOFS_INF_EXPIRING;
@@ -301,6 +299,7 @@ struct dentry *autofs4_expire_direct(struct super_block *sb,
 		spin_unlock(&sbi->fs_lock);
 		return root;
 	}
+out:
 	spin_unlock(&sbi->fs_lock);
 	dput(root);