[SCSI] Remove full sg table memset()

We don't need to do that anymore, since blk_rq_map_sg() clears
individual entries.

Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
index aac8a02..0c86be7 100644
--- a/drivers/scsi/scsi_lib.c
+++ b/drivers/scsi/scsi_lib.c
@@ -764,8 +764,6 @@
 		if (unlikely(!sgl))
 			goto enomem;
 
-		memset(sgl, 0, sizeof(*sgl) * sgp->size);
-
 		/*
 		 * first loop through, set initial index and return value
 		 */