- remove an unnecessary cast and recomputation of (timeout - now);

- remove an unnecessary cast and recomputation of (timeout - now);
- remove useless recomputations of strlen(word) in a loop, and
  normalize the form of complete_peer_helper();
- move LOCAL_USER_ADD() to after the verification of arguments,
  thus removing the need for one LOCAL_USER_REMOVE() call.

The three chunks of the patch are fully disjoint.

git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@15581 65c4cc65-6c06-0410-ace0-fbb531ad65f3