[SCSI] fix up request buffer reference in various scsi drivers

Various scsi drivers use scsi_cmnd.buffer and scsi_cmnd.bufflen in their
queuecommand functions.  Those fields are internal storage for the
midlayer only and are used to restore the original payload after
request_buffer and request_bufflen have been overwritten for EH.  Using
the buffer and bufflen fields means they do very broken things in error
handling.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
diff --git a/drivers/scsi/aacraid/aachba.c b/drivers/scsi/aacraid/aachba.c
index be8dde4c..e4b38f8 100644
--- a/drivers/scsi/aacraid/aachba.c
+++ b/drivers/scsi/aacraid/aachba.c
@@ -961,7 +961,7 @@
 		
 	if(scsicmd->use_sg)
 		pci_unmap_sg(dev->pdev, 
-			(struct scatterlist *)scsicmd->buffer,
+			(struct scatterlist *)scsicmd->request_buffer,
 			scsicmd->use_sg,
 			scsicmd->sc_data_direction);
 	else if(scsicmd->request_bufflen)
@@ -1919,7 +1919,7 @@
 
 	if(scsicmd->use_sg)
 		pci_unmap_sg(dev->pdev, 
-			(struct scatterlist *)scsicmd->buffer,
+			(struct scatterlist *)scsicmd->request_buffer,
 			scsicmd->use_sg,
 			scsicmd->sc_data_direction);
 	else if(scsicmd->request_bufflen)