[ARM] Fix Acorn platform SCSI driver build failures

SCSI folk forgot to fix up all the uses of 'buffer' before deleting
this struct member.  Do it for them to rescue the resulting build
failures.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
diff --git a/drivers/scsi/arm/scsi.h b/drivers/scsi/arm/scsi.h
index 6dd544a..8c2600f 100644
--- a/drivers/scsi/arm/scsi.h
+++ b/drivers/scsi/arm/scsi.h
@@ -74,7 +74,7 @@
 		unsigned long len = 0;
 		int buf;
 
-		SCpnt->SCp.buffer = (struct scatterlist *) SCpnt->buffer;
+		SCpnt->SCp.buffer = (struct scatterlist *) SCpnt->request_buffer;
 		SCpnt->SCp.buffers_residual = SCpnt->use_sg - 1;
 		SCpnt->SCp.ptr = (char *)
 			 (page_address(SCpnt->SCp.buffer->page) +