clone3: clone3_cap_checkpoint_restore: remove unused MAX_PID_NS_LEVEL macro

The macro MAX_PID_NS_LEVEL is never referenced in the code, so remove it.
Signed-off-by: Ba Jing <bajing@cmss.chinamobile.com>
Reviewed-by: Christian Brauner <brauner@kernel.org>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

tools/testing/selftests/clone3/clone3_cap_checkpoint_restore.c

@@ -27,8 +27,6 @@
 #include "../kselftest_harness.h"
 #include "clone3_selftests.h"
 
-#define MAX_PID_NS_LEVEL 32
-
 static void child_exit(int ret)
 {
 	fflush(stdout);