Fix a compiler warning.
Fix a compiler warning.

* subversion/libsvn_subr/cache-membuffer.c
  (initialize_group): Use NO_OFFSET constant instead of -1.


git-svn-id: f8a4e5e023278da1e04e203c7fe051e3c4285d88@1125157 13f79535-47bb-0310-9956-ffa450edef68

YueLinHo/Subversion,wbond/subversion,YueLinHo/Subversion,YueLinHo/Subversion,wbond/subversion,YueLinHo/Subversion,YueLinHo/Subversion,wbond/subversion,YueLinHo/Subversion,wbond/subversion,wbond/subversion,YueLinHo/Subversion,wbond/subversion,wbond/subversion,YueLinHo/Subversion