[SG] Update drivers to use sg helpers

Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
diff --git a/drivers/scsi/imm.c b/drivers/scsi/imm.c
index 74cdc1f..a3d0c6b 100644
--- a/drivers/scsi/imm.c
+++ b/drivers/scsi/imm.c
@@ -705,9 +705,7 @@
 				cmd->SCp.buffer++;
 				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);
 
 				/*
 				 * Make sure that we transfer even number of bytes
@@ -844,9 +842,7 @@
 			cmd->SCp.buffer =
 			    (struct scatterlist *) cmd->request_buffer;
 			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);
 		} else {
 			/* else fill the only available buffer */
 			cmd->SCp.buffer = NULL;