fix(ufs): don't zero out buf before ufs read

ufs_read_blocks always zeros out the buffer before passing
to UFS for DMA. We don't need to zero out buf before reading
from UFS storage, this change remove the memset in ufs_read_blocks.

Signed-off-by: Channa Kadabi <kadabi@google.com>
Change-Id: I8029a7ea07fbd8cce29b383c80a3cfc782c5b7ec
diff --git a/drivers/ufs/ufs.c b/drivers/ufs/ufs.c
index 5c20932..3d6d99f 100644
--- a/drivers/ufs/ufs.c
+++ b/drivers/ufs/ufs.c
@@ -702,7 +702,6 @@
 	       (ufs_params.desc_base != 0) &&
 	       (ufs_params.desc_size >= UFS_DESC_SIZE));
 
-	memset((void *)buf, 0, size);
 	get_utrd(&utrd);
 	ufs_prepare_cmd(&utrd, CDBCMD_READ_10, lun, lba, buf, size);
 	ufs_send_request(utrd.task_tag);