msgb talloc ctx: initialize in all main() scopes

Add msgb_talloc_ctx_init() call to many main() functions still lacking a
msgb talloc context.

Change-Id: Ib0d6751260659cabf18a7ce80680ba2fb4228ea1
diff --git a/openbsc/src/gprs/gtphub_main.c b/openbsc/src/gprs/gtphub_main.c
index 1e20a63..46360f9 100644
--- a/openbsc/src/gprs/gtphub_main.c
+++ b/openbsc/src/gprs/gtphub_main.c
@@ -299,6 +299,7 @@
 	struct gtphub *hub = &_hub;
 
 	osmo_gtphub_ctx = talloc_named_const(NULL, 0, "osmo_gtphub");
+	msgb_talloc_ctx_init(osmo_gtphub_ctx, 0);
 
 	signal(SIGINT, &signal_handler);
 	signal(SIGABRT, &signal_handler);