[SG] Update drivers to use sg helpers

Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
diff --git a/drivers/scsi/NCR5380.c b/drivers/scsi/NCR5380.c
index 988f0bc..2597209 100644
--- a/drivers/scsi/NCR5380.c
+++ b/drivers/scsi/NCR5380.c
@@ -298,8 +298,7 @@
 	if (cmd->use_sg) {
 		cmd->SCp.buffer = (struct scatterlist *) cmd->request_buffer;
 		cmd->SCp.buffers_residual = cmd->use_sg - 1;
-		cmd->SCp.ptr = page_address(cmd->SCp.buffer->page)+
-			       cmd->SCp.buffer->offset;
+		cmd->SCp.ptr = sg_virt(cmd->SCp.buffer);
 		cmd->SCp.this_residual = cmd->SCp.buffer->length;
 	} else {
 		cmd->SCp.buffer = NULL;
@@ -2143,8 +2142,7 @@
 					++cmd->SCp.buffer;
 					--cmd->SCp.buffers_residual;
 					cmd->SCp.this_residual = cmd->SCp.buffer->length;
-					cmd->SCp.ptr = page_address(cmd->SCp.buffer->page)+
-						       cmd->SCp.buffer->offset;
+					cmd->SCp.ptr = sg_virt(cmd->SCp.buffer);
 					dprintk(NDEBUG_INFORMATION, ("scsi%d : %d bytes and %d buffers left\n", instance->host_no, cmd->SCp.this_residual, cmd->SCp.buffers_residual));
 				}
 				/*