In svnsync, don't leave a stray lock when cancelled.
In svnsync, don't leave a stray lock when cancelled.

* subversion/svnsync/main.c
  (maybe_unlock):  New helper.
  (get_lock):  When cancelled, don't leave a stray lock behind.

jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion