NFS: Cleanup if nfs_match_client is interrupted

Don't bail out before cleaning up a new allocation if the wait for
searching for a matching nfs client is interrupted.  Memory leaks.

Reported-by:  <syzbot+7fe11b49c1cc30e3fce2@syzkaller.appspotmail.com>
Fixes: 950a578c ("NFS: make nfs_match_client killable")
Signed-off-by: Benjamin Coddington <bcodding@redhat.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>