L2-input/output: use feature enum type in flag update function

Change-Id: I1f58f441c65fbca101bee2e864bfa6ae2306b475
Signed-off-by: Neale Ranns <nranns@cisco.com>
diff --git a/src/vnet/l2/l2_output.c b/src/vnet/l2/l2_output.c
index 4b93331..31e3f06 100644
--- a/src/vnet/l2/l2_output.c
+++ b/src/vnet/l2/l2_output.c
@@ -612,7 +612,8 @@
 
 /** Enable (or disable) the feature in the bitmap for the given interface. */
 void
-l2output_intf_bitmap_enable (u32 sw_if_index, u32 feature_bitmap, u32 enable)
+l2output_intf_bitmap_enable (u32 sw_if_index,
+			     l2output_feat_masks_t feature_bitmap, u32 enable)
 {
   l2output_main_t *mp = &l2output_main;
   l2_output_config_t *config;