[mgcp] Set the right variable back to NULL
diff --git a/openbsc/src/mgcp/mgcp_protocol.c b/openbsc/src/mgcp/mgcp_protocol.c
index f7ef547..a825e92 100644
--- a/openbsc/src/mgcp/mgcp_protocol.c
+++ b/openbsc/src/mgcp/mgcp_protocol.c
@@ -732,7 +732,7 @@
 
 	if (endp->local_options) {
 		talloc_free(endp->local_options);
-		endp->callid = NULL;
+		endp->local_options = NULL;
 	}
 
 	if (!endp->cfg->early_bind) {