This matches the implementation of the more commonly used unmap_single
routines and the sync_sg_for_cpu method which should provide equivalent
cache maintainance.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Acked-by: NGreentime Hu <greentime@andestech.com>
Tested-by: NGreentime Hu <greentime@andestech.com>