bs11_config: initialize bs11 tall ctx, use instead of bsc ctx

Actually initialize tall_bs11cfg_ctx as named const.

Change-Id: I3b42b29cd1a688cb4c9d1d4e44208509d936e4ef

openbsc/src/utils/bs11_config.c

@@ -890,6 +890,8 @@ int main(int argc, char **argv)
 	struct gsm_network *gsmnet;
 	struct e1inp_line *line;
 
+	tall_bs11cfg_ctx = talloc_named_const(NULL, 0, "bs11-config");
+
 	osmo_init_logging(&log_info);
 	handle_options(argc, argv);
 	bts_model_bs11_init();