Impact: fix guest kernel crash with CONFIG_XEN_SCRUB_PAGES=y
Jens noticed that scrub_page() has a buggy unmap of the wrong
thing. (virtual address instead of page)
Linus pointed out that the whole scrub_page() code is an unnecessary
reimplementation of clear_highpage() to begin with.
Just use clear_highpage() rather than reimplementing it poorly.
Reported-by: Jens Axboe <jens.axboe@oracle.com>
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>