rename gprs_gsup_client.h to gsup_client.h

This is in preparation for moving gsup to libcommon, which is in turn
preparation for libvlr.

Related: OS#1592
Change-Id: I9c95d00f1a9420887a44c938b1d0ee3e20586f4c
diff --git a/openbsc/src/gprs/gsup_test_client.c b/openbsc/src/gprs/gsup_test_client.c
index 901b870..c8ed03d 100644
--- a/openbsc/src/gprs/gsup_test_client.c
+++ b/openbsc/src/gprs/gsup_test_client.c
@@ -9,7 +9,7 @@
 #include <osmocom/core/application.h>
 #include <osmocom/gsm/gsup.h>
 
-#include <openbsc/gprs_gsup_client.h>
+#include <openbsc/gsup_client.h>
 #include <openbsc/debug.h>
 
 static struct gsup_client *g_gc;