Merge r1516429 from trunk:

 * r1516429
   Cast to ensure int size matches format specifier.
   Justification:
     If the error condition triggers the message could be bogus on 32-bit
     platforms.
   Votes:
     +1: philip, danielsh, rhuijben


git-svn-id: https://svn.apache.org/repos/asf/subversion/branches/1.8.x@1516544 13f79535-47bb-0310-9956-ffa450edef68