these have been wrappers for the generic dma direction bits since 2.5.x.
This patch converts the few remaining drivers and removes the macros.

Arjan noticed there's some hunk in here that shouldn't.  Updated patch
below:

Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

scsi_cmnd->serial_number_at_timeout doesn't serve any purpose
anymore.  All serial_number == serial_number_at_timeout tests
are always true in abort callbacks.  Kill the field.  Also, as
->pid always equals ->serial_number and ->serial_number
doesn't have any special meaning anymore, update comments
above ->serial_number accordingly.  Once we remove all uses of
this field from all lldd's, this field should go.

Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!