ifname is checked for interface down event in commit
106fa1e97e ("nl80211: Indicate
interface-down event only for the main netdev"). Do the same for
interface up event to avoid unexpected notifications when the master
interface (e.g., a bridge interface) is set up while then WLAN interface
remains down.
Signed-off-by: Jouni Malinen <jouni@codeaurora.org>