sched/core: Remove double update_rq_clock() in __set_cpus_allowed_ptr_locked()

Since commit d4c64207 ("sched: Cleanup the sched_change NOCLOCK usage"),
update_rq_clock() is called in do_set_cpus_allowed() -> sched_change_begin()
to update the rq clock. This results in a duplicate call update_rq_clock()
in __set_cpus_allowed_ptr_locked().

While holding the rq lock and before calling do_set_cpus_allowed(),
there is nothing that depends on an updated rq_clock.

Therefore, remove the redundant update_rq_clock() in
__set_cpus_allowed_ptr_locked() to avoid the warning about double
rq clock updates.

Fixes: d4c64207 ("sched: Cleanup the sched_change NOCLOCK usage")
Signed-off-by: Hao Jia <jiahao1@lixiang.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: K Prateek Nayak <kprateek.nayak@amd.com>
Link: https://patch.msgid.link/20251029093655.31252-1-jiahao.kernel@gmail.com