const golang.org/x/sys/unix.TUNGETVNETHDRSZ

one use

	golang.org/x/sys/unix (current package)
		zerrors_linux_amd64.go#L504: 	TUNGETVNETHDRSZ                  = 0x800454d7

The pages are generated with Golds v0.7.6. (GOOS=linux GOARCH=amd64)