misc: Fix the return type of the go back vty function...

Without this we will get warnings about incompatible assignments
diff --git a/openbsc/src/bsc_hack.c b/openbsc/src/bsc_hack.c
index 3710440..7be0360 100644
--- a/openbsc/src/bsc_hack.c
+++ b/openbsc/src/bsc_hack.c
@@ -198,7 +198,7 @@
 extern int bts_model_bs11_init(void);
 extern int bts_model_nanobts_init(void);
 
-extern int bsc_vty_go_parent(struct vty *vty);
+extern enum node_type bsc_vty_go_parent(struct vty *vty);
 
 static struct vty_app_info vty_info = {
 	.name 		= "OpenBSC",
diff --git a/openbsc/src/common_vty.c b/openbsc/src/common_vty.c
index 440209a..16d6815 100644
--- a/openbsc/src/common_vty.c
+++ b/openbsc/src/common_vty.c
@@ -35,7 +35,7 @@
 #include <osmocom/vty/vty.h>
 
 
-int bsc_vty_go_parent(struct vty *vty)
+enum node_type bsc_vty_go_parent(struct vty *vty)
 {
 	switch (vty->node) {
 	case GSMNET_NODE:
diff --git a/openbsc/src/gprs/gb_proxy_main.c b/openbsc/src/gprs/gb_proxy_main.c
index 87efb21..32bbe38 100644
--- a/openbsc/src/gprs/gb_proxy_main.c
+++ b/openbsc/src/gprs/gb_proxy_main.c
@@ -185,7 +185,7 @@
 
 extern void *tall_msgb_ctx;
 
-extern int bsc_vty_go_parent(struct vty *vty);
+extern enum node_type bsc_vty_go_parent(struct vty *vty);
 
 static struct vty_app_info vty_info = {
 	.name 		= "Osmocom Gb Proxy",
diff --git a/openbsc/src/gprs/sgsn_main.c b/openbsc/src/gprs/sgsn_main.c
index 6338f70..27d156a 100644
--- a/openbsc/src/gprs/sgsn_main.c
+++ b/openbsc/src/gprs/sgsn_main.c
@@ -125,7 +125,7 @@
 extern struct gprs_ns_inst *bssgp_nsi;
 extern void *tall_msgb_ctx;
 
-extern int bsc_vty_go_parent(struct vty *vty);
+extern enum node_type bsc_vty_go_parent(struct vty *vty);
 
 static struct vty_app_info vty_info = {
 	.name 		= "Osmocom SGSN",
diff --git a/openbsc/src/mgcp/mgcp_main.c b/openbsc/src/mgcp/mgcp_main.c
index 3ccd734..d5b6502 100644
--- a/openbsc/src/mgcp/mgcp_main.c
+++ b/openbsc/src/mgcp/mgcp_main.c
@@ -174,7 +174,7 @@
 	return 0;
 }
 
-extern int bsc_vty_go_parent(struct vty *vty);
+extern enum node_type bsc_vty_go_parent(struct vty *vty);
 
 static struct vty_app_info vty_info = {
 	.name 		= "OpenBSC MGCP",