move gsm_cbfn to gsm_subscriber.h, the only user

(with two less line feeds)

Change-Id: I375e5b021e643f6b1986ea35ebaf3a6d60e189f5

include/osmocom/msc/gsm_data.h

@@ -36,12 +36,6 @@ struct vlr_subscr;
 
 #define tmsi_from_string(str) strtoul(str, NULL, 10)
 
-struct msgb;
-typedef int gsm_cbfn(unsigned int hooknum,
-		     unsigned int event,
-		     struct msgb *msg,
-		     void *data, void *param);
-
 enum {
 	MSC_CTR_LOC_UPDATE_TYPE_ATTACH,
 	MSC_CTR_LOC_UPDATE_TYPE_NORMAL,

include/osmocom/msc/gsm_subscriber.h

@@ -9,6 +9,10 @@
 #include <osmocom/msc/gsm_data.h>
 
 struct ran_conn;
+struct msgb;
+
+typedef int gsm_cbfn(unsigned int hooknum, unsigned int event, struct msgb *msg,
+		     void *data, void *param);
 
 /*
  * Struct for pending channel requests. This is managed in the