selftests/harness: Actually report SKIP for signal tests

Tests that were expecting a signal were not correctly checking for a
SKIP condition. Move the check before the signal checking when
processing test result.

Cc: Shuah Khan <[e-mail]>
Cc: Andy Lutomirski <[e-mail]>
Cc: Will Drewry <[e-mail]>
Cc: [e-mail]
Fixes: 9847d24af95c ("selftests/harness: Refactor XFAIL into SKIP")
Signed-off-by: Kees Cook <[e-mail]>

tools/testing/selftests/kselftest_harness.h

···
 		fprintf(TH_LOG_STREAM,
 			"# %s: Test terminated by timeout\n", t->name);
 	} else if (WIFEXITED(status)) {
-		if (t->termsig != -1) {
+		if (WEXITSTATUS(status) == 255) {
+			/* SKIP */
+			t->passed = 1;
+			t->skip = 1;
+		} else if (t->termsig != -1) {
 			t->passed = 0;
 			fprintf(TH_LOG_STREAM,
 				"# %s: Test exited normally instead of by signal (code: %d)\n",
···
 			/* Success */
 			case 0:
 				t->passed = 1;
-				break;
-			/* SKIP */
-			case 255:
-				t->passed = 1;
-				t->skip = 1;
 				break;
 			/* Other failure, assume step report. */
 			default: