check: Use fail_unless_equals_int instead of fail_if

Makes the error message more interesting
diff --git a/tests/check/elements/udpsink.c b/tests/check/elements/udpsink.c
index 10d7df5..9949ffc 100644
--- a/tests/check/elements/udpsink.c
+++ b/tests/check/elements/udpsink.c
@@ -167,7 +167,7 @@
   gst_check_teardown_element (udpsink);
 
   if (use_buffer_lists)
-    fail_if (data_size != render_list_bytes_received);
+    fail_unless_equals_int (data_size, render_list_bytes_received);
 }
 
 GST_START_TEST (test_udpsink)