KVM: async_pf: Allow to wait for outstanding work

On s390 we are not able to cancel work. Instead we will flush the work and wait for
completion.

Signed-off-by: Dominik Dingel <dingel@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
(cherry picked from commit 9f2ceda49c6b8827c795731c204f6c2587886e2c)
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
1 file changed