BSSAP_Adapter: Split f_bssap_start() from f_bssap_init()

In non-handler mode, the SCCP emulation is currently started before
there's a user registered to SCCP_SP_PORT.  If the first BSSMAP
package arrives from the network, then the SCCP_Emulation will crash
as it cannot deliver the resulting SCCP user primitive to the user.

Let's split start from initialization, so user code can still register
something to SCCP_SP_PORT before starting SCCP_Emulation.

Change-Id: I55c94f18531bb7e5369500dc90f4b0ff3a420774
diff --git a/library/BSSAP_Adapter.ttcn b/library/BSSAP_Adapter.ttcn
index 7f03f33..e50487d 100644
--- a/library/BSSAP_Adapter.ttcn
+++ b/library/BSSAP_Adapter.ttcn
@@ -164,9 +164,12 @@
 		ba.vc_BSSMAP.start(BSSMAP_Emulation.main(valueof(ops), ""));
 	}
 
-	ba.vc_SCCP.start(SCCPStart(ba.sccp_pars));
 
 }
 
+function f_bssap_start(inout BSSAP_Adapter ba) {
+	ba.vc_SCCP.start(SCCPStart(ba.sccp_pars));
+}
+
 
 }