Beacon RSSI is only meaningful in station mode - in ad-hoc mode it
fluctuates, depending on which peer last sent a beacon, and in other
modes it is not set at all.
Fix places in ANI where the beacon RSSI is used to limit their use
to station mode only.
Signed-off-by: NFelix Fietkau <nbd@openwrt.org>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>