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/gprs_subscriber.c b/openbsc/src/gprs/gprs_subscriber.c
index 100fd91..23dbdd4 100644
--- a/openbsc/src/gprs/gprs_subscriber.c
+++ b/openbsc/src/gprs/gprs_subscriber.c
@@ -23,7 +23,7 @@
 #include <osmocom/gsm/protocol/gsm_04_08_gprs.h>
 #include <osmocom/gsm/gsup.h>
 #include <openbsc/gsm_subscriber.h>
-#include <openbsc/gprs_gsup_client.h>
+#include <openbsc/gsup_client.h>
 
 #include <openbsc/sgsn.h>
 #include <openbsc/gprs_sgsn.h>