Update _slabshr fields when updating HQoS masks

Change-Id: Ia1042622c656861a80b856115aeb3c2e5cf5ea2a
Signed-off-by: David Hotham <david.hotham@metaswitch.com>
diff --git a/vnet/vnet/devices/dpdk/cli.c b/vnet/vnet/devices/dpdk/cli.c
index fbd1637..85c3e80 100644
--- a/vnet/vnet/devices/dpdk/cli.c
+++ b/vnet/vnet/devices/dpdk/cli.c
@@ -1328,15 +1328,21 @@
       case 0:
 	xd->hqos_wt[worker_thread_first + i].hqos_field0_slabpos = offset;
 	xd->hqos_wt[worker_thread_first + i].hqos_field0_slabmask = mask;
+	xd->hqos_wt[worker_thread_first + i].hqos_field0_slabshr =
+	  __builtin_ctzll (mask);
 	break;
       case 1:
 	xd->hqos_wt[worker_thread_first + i].hqos_field1_slabpos = offset;
 	xd->hqos_wt[worker_thread_first + i].hqos_field1_slabmask = mask;
+	xd->hqos_wt[worker_thread_first + i].hqos_field1_slabshr =
+	  __builtin_ctzll (mask);
 	break;
       case 2:
       default:
 	xd->hqos_wt[worker_thread_first + i].hqos_field2_slabpos = offset;
 	xd->hqos_wt[worker_thread_first + i].hqos_field2_slabmask = mask;
+	xd->hqos_wt[worker_thread_first + i].hqos_field2_slabshr =
+	  __builtin_ctzll (mask);
       }
 
   return 0;