Fix an RA session leak.
Fix an RA session leak.

* subversion/libsvn_client/util.c
  (svn_client__get_repos_root): Use a subpool for the RA session this
    function creates, and be sure to destroy it during cleanup.


git-svn-id: f8a4e5e023278da1e04e203c7fe051e3c4285d88@869242 13f79535-47bb-0310-9956-ffa450edef68

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