locking/rwsem: Disable preemption in all down_write*() and up_write() code paths

The previous patch has disabled preemption in all the down_read() and
up_read() code paths. For symmetry, this patch extends commit:

  48dfb5d2 ("locking/rwsem: Disable preemption while trying for rwsem lock")

... to have preemption disabled in all the down_write() and up_write()
code paths, including downgrade_write().

Suggested-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Waiman Long <longman@redhat.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20230126003628.365092-4-longman@redhat.com