ptyfs_write() rather than setting a flag and updating these times
through ptyfs_itimes() at some indeterminate time in the future.
However, just use the "time" variable to set the times instead of
using a potentially expensive call to nanotime(). A HZ resolution
on these timestamps is more than enough.
(Possibly incomplete) fix for PR kern/31430.
OK'd be christos@.
30ab8089df