cosmetic: vlr: declare a struct in .h; drop unused header

In vlr_core.h, "pre-declare" a struct used in function declaration.

In vlr_lu_fsm.c, gsup.h is not used, drop the #include.

Change-Id: I61d793c3001abbe6d381be1ae0bb350b07403e88

src/libvlr/vlr_core.h

@@ -2,6 +2,8 @@
 
 #include <osmocom/msc/vlr.h>
 
+struct osmo_gsup_message;
+
 #define LOGGSUPP(level, gsup, fmt, args...) \
 	LOGP(DVLR, level, "GSUP(%s) " fmt, \
 	     (gsup)->imsi, \

src/libvlr/vlr_lu_fsm.c

@@ -21,7 +21,6 @@
 
 #include <osmocom/core/fsm.h>
 #include <osmocom/gsm/gsm48.h>
-#include <osmocom/gsm/gsup.h>
 #include <osmocom/msc/vlr.h>
 #include <osmocom/msc/debug.h>