xdp: fix vlan byte order

Change the byte order of vlan TCI when extracting it
from vlan_hdr in xdp_filter.c. This fixes xdp bypass for vlan tagged
packets, as without the fix flows that are supposed to be bypassed by
the xdp filter are not bypassed.

Ticket: 8699

ebpf/xdp_filter.c

@@ -523,7 +523,7 @@ int SEC("xdp") xdp_hashfilter(struct xdp_md *ctx)
             return XDP_PASS;
         h_proto = vhdr->h_vlan_encapsulated_proto;
 #if VLAN_TRACKING
-        vlan0 = vhdr->h_vlan_TCI & 0x0fff;
+        vlan0 = __constant_ntohs(vhdr->h_vlan_TCI) & 0x0fff;
 #else
         vlan0 = 0;
 #endif
@@ -537,7 +537,7 @@ int SEC("xdp") xdp_hashfilter(struct xdp_md *ctx)
             return XDP_PASS;
         h_proto = vhdr->h_vlan_encapsulated_proto;
 #if VLAN_TRACKING
-        vlan1 = vhdr->h_vlan_TCI & 0x0fff;
+        vlan1 = __constant_ntohs(vhdr->h_vlan_TCI) & 0x0fff;
 #else
         vlan1 = 0;
 #endif