selftests: kselftest_harness: generate test name once

Since we added variant support generating full test case
name takes 4 string arguments. We're about to need it
in another two places. Stop the duplication and print
once into a temporary buffer.
Suggested-by: Jakub Sitnicki <jakub@cloudflare.com>
Acked-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

tools/testing/selftests/kselftest_harness.h

@@ -56,6 +56,7 @@
 #include <asm/types.h>
 #include <ctype.h>
 #include <errno.h>
+#include <limits.h>
 #include <stdbool.h>
 #include <stdint.h>
 #include <stdio.h>
@@ -1107,15 +1108,19 @@ void __run_test(struct __fixture_metadata *f,
 		struct __fixture_variant_metadata *variant,
 		struct __test_metadata *t)
 {
+	char test_name[LINE_MAX];
+
 	/* reset test struct */
 	t->passed = 1;
 	t->skip = 0;
 	t->trigger = 0;
 	memset(t->results->reason, 0, sizeof(t->results->reason));
 
-	ksft_print_msg(" RUN           %s%s%s.%s ...\n",
+	snprintf(test_name, sizeof(test_name), "%s%s%s.%s",
 		 f->name, variant->name[0] ? "." : "", variant->name, t->name);
 
+	ksft_print_msg(" RUN           %s ...\n", test_name);
+
 	/* Make sure output buffers are flushed before fork */
 	fflush(stdout);
 	fflush(stderr);
@@ -1135,15 +1140,14 @@ void __run_test(struct __fixture_metadata *f,
 	} else {
 		__wait_for_test(t);
 	}
-	ksft_print_msg("         %4s  %s%s%s.%s\n", t->passed ? "OK" : "FAIL",
-	       f->name, variant->name[0] ? "." : "", variant->name, t->name);
+	ksft_print_msg("         %4s  %s\n",
+		       t->passed ? "OK" : "FAIL", test_name);
 
 	if (t->skip)
 		ksft_test_result_skip("%s\n", t->results->reason[0] ?
 					t->results->reason : "unknown");
 	else
-		ksft_test_result(t->passed, "%s%s%s.%s\n",
-			f->name, variant->name[0] ? "." : "", variant->name, t->name);
+		ksft_test_result(t->passed, "%s\n", test_name);
 }
 
 static int test_harness_run(int argc, char **argv)