selftests/cgroup: Fix build on older distros

stable inclusion
from stable-v5.10.111
commit e74da71e66142784aa086dbaae047901074b4518
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I5GL1Z

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=e74da71e66142784aa086dbaae047901074b4518

--------------------------------

commit c2e46f6b upstream.

On older distros struct clone_args does not have a cgroup member,
leading to build errors:

 cgroup_util.c: In function 'clone_into_cgroup':
 cgroup_util.c:343:4: error: 'struct clone_args' has no member named 'cgroup'
 cgroup_util.c:346:33: error: invalid application of 'sizeof' to incomplete
  type 'struct clone_args'

But the selftests already have a locally defined version of the
structure which is up to date, called __clone_args.

So use __clone_args which fixes the error.
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
Signed-off-by: NSachin Sant <sachinp@linux.vnet.ibm.com&gt;>
Acked-by: NChristian Brauner <christian.brauner@ubuntu.com>
Signed-off-by: NShuah Khan <skhan@linuxfoundation.org>
Signed-off-by: NOvidiu Panait <ovidiu.panait@windriver.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NZheng Zengkai <zhengzengkai@huawei.com>
Reviewed-by: NWei Li <liwei391@huawei.com>

tools/testing/selftests/cgroup/cgroup_util.c

@@ -330,13 +330,13 @@ pid_t clone_into_cgroup(int cgroup_fd)
 #ifdef CLONE_ARGS_SIZE_VER2
 	pid_t pid;
 
-	struct clone_args args = {
+	struct __clone_args args = {
 		.flags = CLONE_INTO_CGROUP,
 		.exit_signal = SIGCHLD,
 		.cgroup = cgroup_fd,
 	};
 
-	pid = sys_clone3(&args, sizeof(struct clone_args));
+	pid = sys_clone3(&args, sizeof(struct __clone_args));
 	/*
 	 * Verify that this is a genuine test failure:
 	 * ENOSYS -> clone3() not available