Follow-up to r26339, using 'from_same_repos' rather than similar, duplicate code.
Follow-up to r26339, using 'from_same_repos' rather than similar,
duplicate code.

* subversion/libsvn_client/merge.c
  (do_merge, do_single_file_merge): 
   Use 'merge_b->same_repos' rather than custom code to detect the same.
  (from_same_repos):
   Revert the optimization introduced in r25424 for '--dry-run', which does 
   not work for today's state of things.  We always need to determine
   a value for 'merge_cmd_baton->same_repos'.

Suggested by: dlr


git-svn-id: f8a4e5e023278da1e04e203c7fe051e3c4285d88@866436 13f79535-47bb-0310-9956-ffa450edef68

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