Fix a memory problem identified by valgrind.
Fix a memory problem identified by valgrind.

* subversion/libsvn_repos/reporter.c
  (get_revision_info): Don't use stack memory for hash key.

jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion