Bug 613056 - fix coverify Defect Type: Null pointer dereferences issues 11892 - 11939

https://bugzilla.redhat.com/show_bug.cgi?id=613056
Resolves: bug 613056
Bug description: Fix coverify Defect Type: Null pointer dereferences issues 11892 - 11939
description: Catch possible NULL pointer in ldbm_config_get().

ldap/servers/slapd/back-ldbm/ldbm_config.c

@@ -1479,6 +1479,7 @@ void ldbm_config_get(void *arg, config_info *config, char *buf)
     
     if (config == NULL) {
         buf[0] = '\0';
+        return;
     }
     
     switch(config->config_type) {