nfsd: fix fi_delegees leak when fi_had_conflict returns true

Currently, nfs4_set_delegation takes a reference to an existing
delegation and then checks to see if there is a conflict. If there is
one, then it doesn't release that reference.

Change the code to take the reference after the check and only if there
is no conflict.
Signed-off-by: NJeff Layton <jlayton@primarydata.com>
Cc: stable@vger.kernel.org
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

fs/nfsd/nfs4state.c

@@ -3897,11 +3897,11 @@ nfs4_set_delegation(struct nfs4_client *clp, struct svc_fh *fh,
 		status = nfs4_setlease(dp);
 		goto out;
 	}
-	atomic_inc(&fp->fi_delegees);
 	if (fp->fi_had_conflict) {
 		status = -EAGAIN;
 		goto out_unlock;
 	}
+	atomic_inc(&fp->fi_delegees);
 	hash_delegation_locked(dp, fp);
 	status = 0;
 out_unlock: