envoy: Set source identity correctly in access log.
envoy: Set source identity correctly in access log.

Since 22cfad197 the source identity is in the upper 16 bits of the mark.

Fixes: 22cfad197 ("bpf: Use upper 16 bits for identity")
Signed-off-by: Jarno Rajahalme <0f1ab0ac7dffd9db21aa539af2fd4bb04abc3ad4@covalent.io>

tgraf/cilium,tklauser/cilium,michi-covalent/cilium,cilium/cilium,scanf/cilium,eloycoto/cilium,tgraf/cilium,eloycoto/cilium,cilium/cilium,scanf/cilium,cilium/cilium,scanf/cilium,tgraf/cilium,cilium-team/cilium,cilium/cilium,tklauser/cilium,michi-covalent/cilium,tklauser/cilium,cilium/cilium,scanf/cilium,tgraf/cilium,tklauser/cilium,michi-covalent/cilium,michi-covalent/cilium,scanf/cilium,eloycoto/cilium,michi-covalent/cilium,eloycoto/cilium,cilium-team/cilium,tgraf/cilium,tklauser/cilium,scanf/cilium,eloycoto/cilium,eloycoto/cilium,scanf/cilium,tgraf/cilium,eloycoto/cilium