if the next tgt in a cross-realm traversal cannot be
	obtained find_nxt_kdc() was calling krb5_free_creds()
	on the last tgt in the list but was failing to nullify
	the pointer to the cred that was just freed.

	if there were no additional tgts obtained, 
	krb5_get_cred_from_kdc() would return a non-NULL terminated
	cred list to the caller.  This would result in a crash 
	when attempting to manipulate the non-existent cred past
	the end of the list.

	This commit nullifies the credential pointer in 
	find_nxt_kdc() after the call to krb5_free_creds()
	


Commit By: jaltman



Revision: 19195
Changed Files:
U   trunk/src/lib/krb5/krb/gc_frm_kdc.c