selftests/xsk: Ensure traffic validation proceeds after ring size adjustment in xskxceiver

Previously, HW_SW_MIN_RING_SIZE and HW_SW_MAX_RING_SIZE test cases were
not validating Tx/Rx traffic at all due to early return after changing HW
ring size in testapp_validate_traffic().

Fix the flow by checking return value of set_ring_size() and act upon it
rather than terminating the test case there.
Signed-off-by: Tushar Vyavahare <tushar.vyavahare@intel.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: Maciej Fijalkowski <maciej.fijalkowski@intel.com>
Link: https://lore.kernel.org/bpf/20240702055916.48071-2-tushar.vyavahare@intel.com

tools/testing/selftests/bpf/xskxceiver.c

@@ -1899,11 +1899,15 @@ static int testapp_validate_traffic(struct test_spec *test)
 	}
 
 	if (test->set_ring) {
-		if (ifobj_tx->hw_ring_size_supp)
-			return set_ring_size(ifobj_tx);
-
-	ksft_test_result_skip("Changing HW ring size not supported.\n");
-	return TEST_SKIP;
+		if (ifobj_tx->hw_ring_size_supp) {
+			if (set_ring_size(ifobj_tx)) {
+				ksft_test_result_skip("Failed to change HW ring size.\n");
+				return TEST_FAILURE;
+			}
+		} else {
+			ksft_test_result_skip("Changing HW ring size not supported.\n");
+			return TEST_SKIP;
+		}
 	}
 
 	xsk_attach_xdp_progs(test, ifobj_rx, ifobj_tx);