cgroup: remove a NULL check in cgroup_exit()
cgroup: remove a NULL check in cgroup_exit()

init_task.cgroups is initialized at boot phase, and whenver a ask
is forked, it's cgroups pointer is inherited from its parent, and
it's never set to NULL afterwards.

Signed-off-by: Li Zefan <a8167b9d27aca9c6624754deb52c4c6420eded04@huawei.com>
Signed-off-by: Tejun Heo <546b05909706652891a87f7bfe385ae147f61f91@kernel.org>

TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas