l2_packet: Fix bridge workaround for repeater configuration
In repeater configuration, both AP and STA wireless interfaces may be
included into the same bridge. In this case the following race condition
may occur: wpa_supplicant and hostapd are started, then hostapd clients
are connected before wpa_supplicant connects to remote AP. EAPOL packets
between hostapd and its clients are detected by wpa_supplicant on bridge
interface, prematurely disabling the workaround.
One possible option to fix this issue is to check EAPOL destination MAC
in wpa_supplicant and disable workaround only if EAPOL packet on bridge
interface is indeed intended for wpa_supplicant.