timers: round up instead of down in slack_time

On systems with a 100hz tick, this causes handshakes to be retried in
slightly less than 5 seconds, which means they aren't sent at all. This
has the effect of the handshakes entirely stopping their retry cycle
until the next data packet is sent.

Reported-by: Andrew He <andrewhe@mit.edu>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>

0 files changed, 0 insertions, 0 deletions