kunit: use kmemdup in kunit_filter_tests(), take suite as const

kmemdup() is easier than kmalloc() + memcpy(), per lkp bot.

Also make the input `suite` as const since we're now always making
copies after commit a127b154a8 ("kunit: tool: allow filtering test
cases via glob").

Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Daniel Latypov <dlatypov@google.com>
Reviewed-by: David Gow <davidgow@google.com>
Reviewed-by: Brendan Higgins <brendanhiggins@google.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

lib/kunit/executor.c

@@ -55,7 +55,7 @@ static void kunit_parse_filter_glob(struct kunit_test_filter *parsed,
 
 /* Create a copy of suite with only tests that match test_glob. */
 static struct kunit_suite *
-kunit_filter_tests(struct kunit_suite *const suite, const char *test_glob)
+kunit_filter_tests(const struct kunit_suite *const suite, const char *test_glob)
 {
 	int n = 0;
 	struct kunit_case *filtered, *test_case;
@@ -69,11 +69,9 @@ kunit_filter_tests(struct kunit_suite *const suite, const char *test_glob)
 	if (n == 0)
 		return NULL;
 
-	/* Use memcpy to workaround copy->name being const. */
-	copy = kmalloc(sizeof(*copy), GFP_KERNEL);
+	copy = kmemdup(suite, sizeof(*copy), GFP_KERNEL);
 	if (!copy)
 		return ERR_PTR(-ENOMEM);
-	memcpy(copy, suite, sizeof(*copy));
 
 	filtered = kcalloc(n + 1, sizeof(*filtered), GFP_KERNEL);
 	if (!filtered)