where the same, or nearly the same code is used to pci_unmap
data buffers of driver initiated commands.  Factor these out
into a separate function.
Signed-off-by: Stephen M. Cameron <scameron@beardog.cce.hp.com>
Cc: James Bottomley <James.Bottomley@HansenPartnership.com>
Cc: Jens Axboe <jens.axboe@oracle.com>
Cc: Mike Miller <mikem@beardog.cce.hp.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>