gprs: Rename gprs_subscr_delete to gprs_subscr_cleanup

The old name is somewhat misleading. The function is rather preparing
the subscriber for a subsequent subscr_free, that is possibly invoked
by a subscr_put. It detaches the subscriber from the MM context and
optionally invokes a PURGE_MS procedure. Therefore the _cleanup
suffix is chosen (see mm_ctx_cleanup_free).

Sponsored-by: On-Waves ehf
diff --git a/openbsc/tests/sgsn/sgsn_test.c b/openbsc/tests/sgsn/sgsn_test.c
index 57577a4..5d142da 100644
--- a/openbsc/tests/sgsn/sgsn_test.c
+++ b/openbsc/tests/sgsn/sgsn_test.c
@@ -269,7 +269,7 @@
 	OSMO_ASSERT(last_updated_subscr == s1);
 
 	/* There is no subscriber cache. Verify it */
-	gprs_subscr_delete(s1);
+	gprs_subscr_cleanup(s1);
 	subscr_put(s1);
 	s1 = NULL;
 	sfound = gprs_subscr_get_by_imsi(imsi1);
@@ -279,7 +279,7 @@
 	assert_subscr(s3, imsi3);
 
 	/* Free entry 2 (GSM_SUBSCRIBER_FIRST_CONTACT is set) */
-	gprs_subscr_delete(s2);
+	gprs_subscr_cleanup(s2);
 	subscr_put(s2);
 	s2 = NULL;
 	OSMO_ASSERT(gprs_subscr_get_by_imsi(imsi1) == NULL);
@@ -287,7 +287,7 @@
 	assert_subscr(s3, imsi3);
 
 	/* Try to delete entry 3 */
-	gprs_subscr_delete(s3);
+	gprs_subscr_cleanup(s3);
 	subscr_put(s3);
 	s3 = NULL;
 	OSMO_ASSERT(gprs_subscr_get_by_imsi(imsi3) == NULL);