Minor type consistency fix.
Minor type consistency fix.

* subversion/libsvn_subr/cache-membuffer.c
  (last_access_key_t): APR defines key sizes as signed, so let's do the same

git-svn-id: f8a4e5e023278da1e04e203c7fe051e3c4285d88@1543601 13f79535-47bb-0310-9956-ffa450edef68

YueLinHo/Subversion,YueLinHo/Subversion,YueLinHo/Subversion,YueLinHo/Subversion,YueLinHo/Subversion,YueLinHo/Subversion,YueLinHo/Subversion,YueLinHo/Subversion