Document and clean up some client commit code.
Document and clean up some client commit code.

* subversion/libsvn_client/commit_util.c
  (file_mod_t): Constify the 'item' pointer so we can assign it from a const
    pointer in do_item_commit().
  (do_item_commit): Add better documentation. Constify the local 'item'
    pointer to help understand the function's semantics. Remove a redundant
    initialization, to help tools help us find mistakes. Remove an under-
    used local variable, for clarity.
  (svn_client__do_commit): Initialize variables at their declaration.
    Remove an under-used local variable.


git-svn-id: f8a4e5e023278da1e04e203c7fe051e3c4285d88@938039 13f79535-47bb-0310-9956-ffa450edef68

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