On the verify-keep-going-branch, restore display of error codes in the
summary, which I accidentally removed in r1546041.

* subversion/svnadmin/svnadmin.c
  (repos_notify_handler): Display error codes in the summary.


git-svn-id: https://svn.apache.org/repos/asf/subversion/branches/verify-keep-going@1546046 13f79535-47bb-0310-9956-ffa450edef68