IB/iser: Fix wrong calculation of protection buffer length

This length miss-calculation may cause a silent data corruption
in the DIX case and cause the device to reference unmapped area.

Fixes: d77e65350f2d ('libiscsi, iser: Adjust data_length to include protection information')
Signed-off-by: Sagi Grimberg <sagig@mellanox.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>
diff --git a/drivers/infiniband/ulp/iser/iser_initiator.c b/drivers/infiniband/ulp/iser/iser_initiator.c
index 20e859a..76eb57b 100644
--- a/drivers/infiniband/ulp/iser/iser_initiator.c
+++ b/drivers/infiniband/ulp/iser/iser_initiator.c
@@ -409,8 +409,8 @@
 	if (scsi_prot_sg_count(sc)) {
 		prot_buf->buf  = scsi_prot_sglist(sc);
 		prot_buf->size = scsi_prot_sg_count(sc);
-		prot_buf->data_len = data_buf->data_len >>
-				     ilog2(sc->device->sector_size) * 8;
+		prot_buf->data_len = (data_buf->data_len >>
+				     ilog2(sc->device->sector_size)) * 8;
 	}
 
 	if (hdr->flags & ISCSI_FLAG_CMD_READ) {