staging: vt6656: Power save stop wake_up_count wrap around.

staging: vt6656: Power save stop wake_up_count wrap around.

conf.listen_interval can sometimes be zero causing wake_up_count
to wrap around up to many beacons too late causing
CTRL-EVENT-BEACON-LOSS as in.

wpa_supplicant[795]: message repeated 45 times: [..CTRL-EVENT-BEACON-LOSS ]

Fixes: 43c93d9bf5e2 ("staging: vt6656: implement power saving code.")
Cc: stable <[email protected]>
Signed-off-by: Malcolm Priestley <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Greg Kroah-Hartman <[email protected]>