Fix a "condition depends on unitialized value" error found with valgrind.

* subversion/libsvn_fs_fs/pack.c
  (sort_reps_range): Assign REP_ID only where needed but make sure it
                     gets initialized, and to the first *relevant* entry.

Found by: kotkov


git-svn-id: https://svn.apache.org/repos/asf/subversion/trunk@1572512 13f79535-47bb-0310-9956-ffa450edef68
* subversion/libsvn_fs_fs/pack.c
  (sort_reps): Remove redundant commentary.  No functional change.


git-svn-id: https://svn.apache.org/repos/asf/subversion/trunk@1572514 13f79535-47bb-0310-9956-ffa450edef68