[SCSI] More buffer->request_buffer changes

Seem like quite a few splipped through the cracks.  Here's a patch to
update all references I could find:

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
diff --git a/drivers/scsi/mac53c94.c b/drivers/scsi/mac53c94.c
index 93edaa8..89ef34d 100644
--- a/drivers/scsi/mac53c94.c
+++ b/drivers/scsi/mac53c94.c
@@ -378,7 +378,7 @@
 		int nseg;
 
 		total = 0;
-		scl = (struct scatterlist *) cmd->buffer;
+		scl = (struct scatterlist *) cmd->request_buffer;
 		nseg = pci_map_sg(state->pdev, scl, cmd->use_sg,
 				cmd->sc_data_direction);
 		for (i = 0; i < nseg; ++i) {