Fix a UI niggle:  don't print an update summary header with no content when excluding WC items:
Fix a UI niggle:  don't print an update summary header with no content
when excluding WC items:

   $ svn update --set-depth exclude wc/A/*
   D    wc/A/B
   D    wc/A/C
   D    wc/A/D
   D    wc/A/mu
   Summary of updates:    <<< This line removed by this commit
   $

* subversion/svn/update-cmd.c
  (print_update_summary): Delay the printing of the update summary
    header until we're sure there's a summary item to report.


git-svn-id: f8a4e5e023278da1e04e203c7fe051e3c4285d88@1439480 13f79535-47bb-0310-9956-ffa450edef68

YueLinHo/Subversion,YueLinHo/Subversion,YueLinHo/Subversion,YueLinHo/Subversion,YueLinHo/Subversion,YueLinHo/Subversion,YueLinHo/Subversion,YueLinHo/Subversion