bsc: A BTS excluded from the RF lock should be allowed to make a connection

When introducing the exclude for the BTS lock the RF stayed up but
all connections were immediately released. Optionally pass the BTS
as second parameter and check the exclude bit.

Tested-with: rf-lock-exclude/RFLockExcludeTest.st
diff --git a/openbsc/src/osmo-bsc/osmo_bsc_sccp.c b/openbsc/src/osmo-bsc/osmo_bsc_sccp.c
index 37eb1b7..3533d6d 100644
--- a/openbsc/src/osmo-bsc/osmo_bsc_sccp.c
+++ b/openbsc/src/osmo-bsc/osmo_bsc_sccp.c
@@ -190,12 +190,9 @@
 int bsc_create_new_connection(struct gsm_subscriber_connection *conn,
 			      struct osmo_msc_data *msc)
 {
-	struct gsm_network *net;
 	struct osmo_bsc_sccp_con *bsc_con;
 	struct sccp_connection *sccp;
 
-	net = conn->bts->network;
-
 	/* This should not trigger */
 	if (!msc->msc_con->is_authenticated) {
 		LOGP(DMSC, LOGL_ERROR,
@@ -203,7 +200,7 @@
 		return -1;
 	}
 
-	if (!bsc_grace_allow_new_connection(net)) {
+	if (!bsc_grace_allow_new_connection(conn->bts->network, conn->bts)) {
 		LOGP(DMSC, LOGL_NOTICE, "BSC in grace period. No new connections.\n");
 		return -1;
 	}