FROMGIT: sched: Always clear user_cpus_ptr in do_set_cpus_allowed()

The do_set_cpus_allowed() function is used by either kthread_bind() or
select_fallback_rq(). In both cases the user affinity (if any) should be
destroyed too.

Change-Id: I9da8961ebeefa2ac1d42eec3ea80ae2cbdddf485
Suggested-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Waiman Long <longman@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20220922180041.1768141-6-longman@redhat.com
BUG: 254447891
(cherry picked from commit 0083fbe7953602c341454889af01ada601ffac3b
 https://git.kernel.org/pub/scm/linux/kernel/git/peterz/queue.git

 sched/core))
Signed-off-by: Ashay Jaiswal <quic_ashayj@quicinc.com>