NFSv4: Fix two infinite loops in the mount code

We can currently loop forever in nfs4_lookup_root() and in
nfs41_proc_secinfo_no_name(), if the first iteration returns a
NFS4ERR_DELAY or something else that causes exception.retry to get
set.
Reported-by: Weston Andros Adamson <dros@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Cc: stable@vger.kernel.org

fs/nfs/nfs4proc.c

@@ -2290,11 +2290,12 @@ static int nfs4_lookup_root(struct nfs_server *server, struct nfs_fh *fhandle,
 		switch (err) {
 		case 0:
 		case -NFS4ERR_WRONGSEC:
-			break;
+			goto out;
 		default:
 			err = nfs4_handle_exception(server, err, &exception);
 		}
 	} while (exception.retry);
+out:
 	return err;
 }
 
@@ -6229,11 +6230,12 @@ nfs41_proc_secinfo_no_name(struct nfs_server *server, struct nfs_fh *fhandle,
 		case 0:
 		case -NFS4ERR_WRONGSEC:
 		case -NFS4ERR_NOTSUPP:
-			break;
+			goto out;
 		default:
 			err = nfs4_handle_exception(server, err, &exception);
 		}
 	} while (exception.retry);
+out:
 	return err;
 }