[PATCH] reconnect_one(): fix a missing error code

[Dan Carpenter <dan.carpenter@oracle.com>]

I found this bug by reviewing places where we do ERR_PTR(0) (which is
NULL).

We used to return an error pointer if lookup_one_len() failed but we
moved this code into a helper function and accidentally removed that.
NULL is a valid return for this function but it's not what we intended.

Fixes: bbf7a8a3562f ("exportfs: move most of reconnect_path to helper function")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>

diff --git a/fs/exportfs/expfs.c b/fs/exportfs/expfs.c
index 329a5d103846..451237745689 100644
--- a/fs/exportfs/expfs.c
+++ b/fs/exportfs/expfs.c
@@ -147,6 +147,7 @@ static struct dentry *reconnect_one(struct vfsmount *mnt,
 	tmp = lookup_one_len_unlocked(nbuf, parent, strlen(nbuf));
 	if (IS_ERR(tmp)) {
 		dprintk("%s: lookup failed: %d\n", __func__, PTR_ERR(tmp));
+		err = PTR_ERR(tmp);
 		goto out_err;
 	}
 	if (tmp != dentry) {