move gsm_auth_tuple to vlr.h as vlr_auth_tuple

Along goes GSM_KEYSEQ_INVAL as VLR_*.

It's where it logically belongs, and is almost the only reason why vlr.h
includes gsm_data.h. The remaining reason, GSM_EXTENSION_LENGTH, will be moved
by upcoming patch.

Change-Id: I122feae7ee3cbc59e941daef35a954bce29fec76
diff --git a/src/libmsc/msc_vty.c b/src/libmsc/msc_vty.c
index b632117..aaefb0b 100644
--- a/src/libmsc/msc_vty.c
+++ b/src/libmsc/msc_vty.c
@@ -602,7 +602,7 @@
 #endif
 
 	if (vsub->last_tuple) {
-		struct gsm_auth_tuple *t = vsub->last_tuple;
+		struct vlr_auth_tuple *t = vsub->last_tuple;
 		vty_out(vty, "    A3A8 last tuple (used %d times):%s",
 			t->use_count, VTY_NEWLINE);
 		vty_out(vty, "     seq # : %d%s",