Comment 4 for bug 1821625

> After these patches are applied to bionic, both libseccomp and systemd
> will need to be rebuilt - libseccomp rebuilt against the kernel
> headers, and systemd against the libseccomp headers.

technically both will need to be rebuilt against the new kernel headers, but systemd doesn't need to wait for libseccomp to be rebuilt, as it should get the correct value as soon as the kernel headers are updated, since the libseccomp header file only defines __NR_pkey_mprotect (as an invalid value) if the kernel header doesn't define it.