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/tests/bsc-nat/bsc_nat_test.c b/openbsc/tests/bsc-nat/bsc_nat_test.c
index b531c6b..2914a01 100644
--- a/openbsc/tests/bsc-nat/bsc_nat_test.c
+++ b/openbsc/tests/bsc-nat/bsc_nat_test.c
@@ -1551,6 +1551,7 @@
 
 int main(int argc, char **argv)
 {
+	msgb_talloc_ctx_init(NULL, 0);
 	sccp_set_log_area(DSCCP);
 	osmo_init_logging(&log_info);