Share the code for the global and per-page flush map_sg loops using a
simple bool parameter to disable the per-page flush for the former
variant.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reported-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: David S. Miller <davem@davemloft.net>