Ticket 47740 - Fix coverity issues: null deferences - Part 6
12474 - Null pointer dereference - ldap/servers/slapd/tools/migratecred.c
12473 - Null pointer dereference - ldap/srevers/slapd/snmp/main.c
12468 - Null pointer dereference - ldap/servers/plugins/memberof/memberof.c
https://fedorahosted.org/389/ticket/47740
Reviewed by: rmeggins(Thanks!)
(cherry picked from commit d39807865d63244236ef2dcbd36d74ae857419a3)