libctrl: Change controlif_setup so it returns the ctrl handle

nat: Catch up with controlif_setup API change
We now save a control handle reference in the nat
osmo-bsc: Catch up with controlif_setup API change
We now save a control handle reference in the gsm network
diff --git a/openbsc/src/osmo-bsc_nat/bsc_nat.c b/openbsc/src/osmo-bsc_nat/bsc_nat.c
index 295535a..b9d4639 100644
--- a/openbsc/src/osmo-bsc_nat/bsc_nat.c
+++ b/openbsc/src/osmo-bsc_nat/bsc_nat.c
@@ -39,12 +39,14 @@
 #include <openbsc/bsc_msc.h>
 #include <openbsc/bsc_nat.h>
 #include <openbsc/bsc_nat_sccp.h>
-#include <openbsc/control_cmd.h>
 #include <openbsc/ipaccess.h>
 #include <openbsc/abis_nm.h>
 #include <openbsc/socket.h>
 #include <openbsc/vty.h>
 
+#include <openbsc/control_cmd.h>
+#include <openbsc/control_if.h>
+
 #include <osmocom/core/application.h>
 #include <osmocom/core/talloc.h>
 
@@ -1760,7 +1762,7 @@
 		exit(1);
 	}
 
-	controlif_setup(NULL, 4250);
+	nat->ctrl = controlif_setup(NULL, 4250);
 	ctrl_cmd_install(CTRL_NODE_ROOT, &cmd_fwd_cmd);
 
 	nat->msc_con->connection_loss = msc_connection_was_lost;