selftests: Uninitialized variable in test_cgcore_proc_migration()

The "c_threads" variable is used in the error handling code before it
has been initialized

Fixes: 11318989 ("selftests: cgroup: Add task migration tests")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Acked-by: Michal Koutný <mkoutny@suse.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

tools/testing/selftests/cgroup/test_core.c

@@ -369,7 +369,7 @@ static void *dummy_thread_fn(void *arg)
 static int test_cgcore_proc_migration(const char *root)
 {
 	int ret = KSFT_FAIL;
-	int t, c_threads, n_threads = 13;
+	int t, c_threads = 0, n_threads = 13;
 	char *src = NULL, *dst = NULL;
 	pthread_t threads[n_threads];