[PATCH V2] selftests/cgroup: Fix build on older distros

[Sachin Sant]

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: Michael Ellerman <m...@ellerman.id.au>
Signed-off-by: Sachin Sant <sach...@linux.vnet.ibm.com>>
Acked-by: Christian Brauner <christian.brau...@ubuntu.com>
---

V2: Replace all instances of clone_args by __clone_args
---

diff --git a/a/tools/testing/selftests/cgroup/cgroup_util.c 
b/b/tools/testing/selftests/cgroup/cgroup_util.c
index 05853b0..0270146 100644
--- a/a/tools/testing/selftests/cgroup/cgroup_util.c
+++ b/b/tools/testing/selftests/cgroup/cgroup_util.c
@@ -337,13 +337,13 @@ 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