sgsn: Refactor sgsn_auth to separate request and authorization

Currently the authorization is done in sgsn_auth_request for ACL
based authorization. This doesn't match the way remote authorization
would work, so that there is a second call to sgsn_auth_state already
present in sgsn_auth_update.

This patch removes the autorization check completely from
sgsn_auth_request which in turn calls sgsn_auth_update directly now.

Sponsored-by: On-Waves ehf
diff --git a/openbsc/src/gprs/gprs_sgsn.c b/openbsc/src/gprs/gprs_sgsn.c
index daf9483..9fc4b86 100644
--- a/openbsc/src/gprs/gprs_sgsn.c
+++ b/openbsc/src/gprs/gprs_sgsn.c
@@ -451,11 +451,9 @@
 	return gsm0408_gprs_force_reattach_oldmsg(oldmsg);
 }
 
-void sgsn_update_subscriber_data(struct sgsn_mm_ctx *mmctx,
-				 struct sgsn_subscriber_data *sd)
+void sgsn_update_subscriber_data(struct sgsn_mm_ctx *mmctx)
 {
 	OSMO_ASSERT(mmctx);
 
-	if (sd->auth_state != mmctx->auth_state)
-		sgsn_auth_update(mmctx, sd);
+	sgsn_auth_update(mmctx, sgsn);
 }