[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/sun3_NCR5380.c b/drivers/scsi/sun3_NCR5380.c
index 2ebe0d6..2f8073b 100644
--- a/drivers/scsi/sun3_NCR5380.c
+++ b/drivers/scsi/sun3_NCR5380.c
@@ -517,7 +517,7 @@
      */
 
     if (cmd->use_sg) {
-	cmd->SCp.buffer = (struct scatterlist *) cmd->buffer;
+	cmd->SCp.buffer = (struct scatterlist *) cmd->request_buffer;
 	cmd->SCp.buffers_residual = cmd->use_sg - 1;
 	cmd->SCp.ptr = (char *) SGADDR(cmd->SCp.buffer);
 	cmd->SCp.this_residual = cmd->SCp.buffer->length;