cnat: Fix backend LB

Type: fix

Change-Id: I4ea263270bcc38e505e88d512acacef7439f3823
Signed-off-by: Nathan Skrzypczak <nathan.skrzypczak@gmail.com>
diff --git a/src/plugins/cnat/cnat_node_vip.c b/src/plugins/cnat/cnat_node_vip.c
index 224dd1c..5c1e0e4 100644
--- a/src/plugins/cnat/cnat_node_vip.c
+++ b/src/plugins/cnat/cnat_node_vip.c
@@ -160,7 +160,7 @@
       hash_c0 = (AF_IP4 == ctx->af ?
 		 ip4_compute_flow_hash (ip4, lb0->lb_hash_config) :
 		 ip6_compute_flow_hash (ip6, lb0->lb_hash_config));
-      bucket0 = hash_c0 & lb0->lb_n_buckets_minus_1;
+      bucket0 = hash_c0 % lb0->lb_n_buckets;
       dpo0 = load_balance_get_fwd_bucket (lb0, bucket0);
 
       /* add the session */