Install zgenhostid to sbindir

zgenhostid(8) is used to modify or create /etc/hostid. This
administrative tool is currently installed to bindir. System utilities
are typically placed in sbin.

Modify the installation directory for zgenhostid. Additionally, track
this change in its use in dracut and the rpm installation.

Authored-by: наб <nabijaczleweli@nabijaczleweli.xyz>
Authored-by: Antonio Russo <aerusso@aerusso.net>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Antonio Russo <aerusso@aerusso.net>
Closes #11485