Add -F to flush output after each write.  With this, I can
set up a pipe and allow a jr user to watch what I'm doing
by running 'script -F pipefile' on it.

While here, spell out the month in the .Dd tag like other
manual pages.
Make panic_reboot_wait_time static.

Submitted by:	jhb
Fix external compiler warning about write-only assigned variable.
[automated] Merge in upstream-github/master