split bsc_bootstrap_network() in alloc and config

For patch clarity, keep some code dup to be removed in a subsequent patch. In
the same sense don't change the fact that mncc_sock_init()'s return value is
ignored.

The global gsm_network instance 'bsc_gsmnet' is basically only used by the VTY,
and a future patch will "hide" that global in a vty .c file. In a nutshell, I
want to

- first allocate a gsm_network,
- then initialize the VTY passing the gsm_network pointer,
- and then read the config file using the initialized VTY.

So far, bsc_bootstrap_network() allocates the gsm_network and reads the config
file right away, which only works by sharing the extern bsc_gsmnet pointer,
which I would like to uncouple.

Change-Id: I480a09a31a79766ad07b627dd5238b7e37f3be7a
diff --git a/openbsc/src/osmo-bsc/osmo_bsc_main.c b/openbsc/src/osmo-bsc/osmo_bsc_main.c
index daab55b..b6b1ae1 100644
--- a/openbsc/src/osmo-bsc/osmo_bsc_main.c
+++ b/openbsc/src/osmo-bsc/osmo_bsc_main.c
@@ -220,8 +220,12 @@
 	/* initialize SCCP */
 	sccp_set_log_area(DSCCP);
 
-
-	rc = bsc_bootstrap_network(NULL, config_file);
+	rc = bsc_network_alloc(NULL);
+	if (rc) {
+		fprintf(stderr, "Allocation failed. exiting.\n");
+		exit(1);
+	}
+	rc = bsc_network_configure(config_file);
 	if (rc < 0) {
 		fprintf(stderr, "Bootstrapping the network failed. exiting.\n");
 		exit(1);