Bug 1083449 - ifc_enable / ifc_disable needs to be protected as well. r=vchang
Bug 1087153 - Only attempt to close p2p supplicant connection before KK. r=vchang.

Since we would only use single connection to communicate with wpa_supplicant
on different interface (wlan0/p2p0) since KK, there's no need to close
supplicant connection in the p2p state machine.