This commit fixes the nl80211 driver call get_inact_sec() to return -1
when STA inactivity time retrieval fails in i802_read_sta_data().
This was intended to be handled by initalizing the inactive_msec member
to -1 but i802_read_sta_data() assumes the data parameter is
uninitialized and memsets the entire structure, neutralizing the attempt
to distinguish between no value (-1) and a time value of 0.
This is fixed by now requiring i802_read_sta_data() callers to
initialize the data structure first (allowing get_inact_sec() to use
-1). This is a safe change because it does not change any driver API
behavior and only affects one other static function in driver_nl80211.c
Signed-off-by: Joel Cunningham <joel.cunningham@me.com>
7824bf77d6