Fix an "unreachable code" warning introduced in r1096150.
Fix an "unreachable code" warning introduced in r1096150.

* subversion/svnadmin/main.c
  (subcommand_crashtest): use SVN_ERR_MALFUNCTION instead of abort()

Found by: hwright
Suggested by: rhuijben

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