const golang.org/x/sys/unix.NFT_CT_SRC_IP6

one use

	golang.org/x/sys/unix (current package)
		ztypes_linux.go#L2325: 	NFT_CT_SRC_IP6                    = 0x15

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