reboot: Allow this to be installed as nextboot

[imp]

Summary

Allow nextboot to be a symlink link to reboot. It does everything reboot
does, except doesn't actually setup the sytem to reboot and reboot. Also,
don't accept the reboot args related to rebooting when in nextboot mode.

Sponsored by: Netflix

[imp]

review comments

[kib]

sbin/reboot/reboot.c

298

[emaste]

sbin/reboot/reboot.c

197

Instead of having to repeat this many times, what about having a per-prog getopt string?

268

[imp]

sbin/reboot/reboot.c

268

Pre-existing style though, which i try not to gratuitously not change...

[imp]

fold in ed's suggestion and add {} around the while loop to reflect updated
practices since this code was written.

[imp]

oops, missed one