arm 32bit: Couldn't write '4194304' to 'kernel/pid_max': Invalid argument

[asavah]

systemd version the issue has been seen with
master @e7b621e

Used distribution
own OS, rpi3, 32bit armhf

Expected behaviour you didn't see
systemd-sysctl.service starts without errors

Unexpected behaviour you saw

 May 18 04:57:03 rpi3 systemd-sysctl[226]: Couldn't write '4194304' to 'kernel/pid_max': Invalid argument
May 18 04:57:03 rpi3 systemd[1]: systemd-sysctl.service: Main process exited, code=exited, status=1/FAILURE
May 18 04:57:03 rpi3 systemd[1]: systemd-sysctl.service: Failed with result 'exit-code'.

Steps to reproduce the problem
Boot a 32bit os with systemd

Possible cause
For 32bit systems pid_max maximum value is 32768,
from man 5 proc

 On 32-bit platforms, 32768 is the maximum value for pid_max.

The target OS "bitness" should be considered when generating /usr/lib/sysctl.d/50-default.conf