mac80211: fix regression in sta connection monitor

When a frame was acked and probe frames were sent, the connection monitoring
needs to be reset, otherwise it will keep probing until the connection is
considered dead, even though frames have been acked in the mean time.

Fixes: 9abf4e49 ("mac80211: optimize station connection monitor")
Reported-by: Georgi Valkov <gvalkov@abv.bg>
Signed-off-by: Felix Fietkau <nbd@nbd.name>
Link: https://lore.kernel.org/r/20200927105605.97954-1-nbd@nbd.name


Signed-off-by: Johannes Berg <johannes.berg@intel.com>