ztest: Don't clear test stats before running suite

test_main can call ztest_run_all multiple times. For example
tests/bluetooth/host/keys/bt_keys_get_addr/src/main.c does so.  If the
first call skips some tests and then they run in the second call,
everything is fine. However if they passed or failed in the first run
and skipped in the second run, then the test output (json, xml, and
printed summary) show the test as skipped even though it ran.

The solution is to not clear the test stats.

__ztest_init_unit_test_result_for_suite was added in commit
996c845 by nashif.

Signed-off-by: Jeremy Bettis <jbettis@google.com>

Author: jeremybettis

subsys/testsuite/ztest/src/ztest.c

@@ -921,19 +921,6 @@ int z_ztest_run_test_suite(const char *name, bool shuffle,
 K_APPMEM_PARTITION_DEFINE(ztest_mem_partition);
 #endif
 
-static void __ztest_init_unit_test_result_for_suite(struct ztest_suite_node *suite)
-{
-	struct ztest_unit_test *test = NULL;
-
-	while (((test = z_ztest_get_next_test(suite->name, test)) != NULL)) {
-		test->stats->run_count = 0;
-		test->stats->skip_count = 0;
-		test->stats->fail_count = 0;
-		test->stats->pass_count = 0;
-		test->stats->duration_worst_ms = 0;
-	}
-}
-
 /* Show one line summary for a test suite.
  */
 static void __ztest_show_suite_summary_oneline(struct ztest_suite_node *suite)
@@ -1091,9 +1078,6 @@ int z_impl_ztest_run_test_suites(const void *state, bool shuffle, int suite_iter
 	memset(suites_to_run, 0, ZTEST_SUITE_COUNT * sizeof(struct ztest_suite_node *));
 	z_ztest_shuffle(shuffle, (void **)suites_to_run, (intptr_t)_ztest_suite_node_list_start,
 			ZTEST_SUITE_COUNT, sizeof(struct ztest_suite_node));
-	for (size_t i = 0; i < ZTEST_SUITE_COUNT; ++i) {
-		__ztest_init_unit_test_result_for_suite(suites_to_run[i]);
-	}
 	for (size_t i = 0; i < ZTEST_SUITE_COUNT; ++i) {
 		count += __ztest_run_test_suite(suites_to_run[i], state, shuffle, suite_iter,
 						case_iter, param);
@@ -1108,7 +1092,6 @@ int z_impl_ztest_run_test_suites(const void *state, bool shuffle, int suite_iter
 #else
 	for (struct ztest_suite_node *ptr = _ztest_suite_node_list_start;
 	     ptr < _ztest_suite_node_list_end; ++ptr) {
-		__ztest_init_unit_test_result_for_suite(ptr);
 		count += __ztest_run_test_suite(ptr, state, shuffle, suite_iter, case_iter, param);
 		/* Stop running tests if we have a critical error or if we have a failure and
 		 * FAIL_FAST was set
@@ -1365,7 +1348,6 @@ static int cmd_run_suite(const struct shell *sh, size_t argc, char **argv)
 
 	for (struct ztest_suite_node *ptr = _ztest_suite_node_list_start;
 	     ptr < _ztest_suite_node_list_end; ++ptr) {
-		__ztest_init_unit_test_result_for_suite(ptr);
 		if (strcmp(shell_command, "run-testcase") == 0) {
 			count += __ztest_run_test_suite(ptr, NULL, shuffle, 1, repeat_iter, param);
 		} else if (strcmp(shell_command, "run-testsuite") == 0) {