clm.c:
defect 639
fix segfault if null callback parameter passed to saClmInitialize

BKrev: 42b31b3dnxjnqS8cEzAPHPJmbMdVEw


git-svn-id: http://svn.fedorahosted.org/svn/corosync/trunk@697 fd59a12c-fef9-0310-b244-a6a79926bd2f