Fix memory leak when diff is given multiple files on the command line.
Fix memory leak when diff is given multiple files on the command line.

* subversion/clients/cmdline/diff-cmd.c
  (svn_cl__diff): Rename subpool to iterpool.
  Pass iterpool to children, instead of pool.
  Clear iterpool on both branches.



git-svn-id: f8a4e5e023278da1e04e203c7fe051e3c4285d88@857592 13f79535-47bb-0310-9956-ffa450edef68

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