[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/fc4/fc.c b/drivers/fc4/fc.c
index 66d03f2..1a159e8 100644
--- a/drivers/fc4/fc.c
+++ b/drivers/fc4/fc.c
@@ -429,7 +429,7 @@
 		
 		if (fcmd->data) {
 			if (SCpnt->use_sg)
-				dma_unmap_sg(fc->dev, (struct scatterlist *)SCpnt->buffer,
+				dma_unmap_sg(fc->dev, (struct scatterlist *)SCpnt->request_buffer,
 						SCpnt->use_sg,
 						SCpnt->sc_data_direction);
 			else
@@ -810,7 +810,7 @@
 							     SCpnt->request_bufflen,
 							     SCpnt->sc_data_direction);
 			} else {
-				struct scatterlist *sg = (struct scatterlist *)SCpnt->buffer;
+				struct scatterlist *sg = (struct scatterlist *)SCpnt->request_buffer;
 				int nents;
 
 				FCD(("XXX: Use_sg %d %d\n", SCpnt->use_sg, sg->length))