Commit 1aef400bf03159d60109ce886943fbd26d88a6c3 implemented IBSS RSN
disconnect() call using sta_deauth() in a way that resulted in NULL
pointer dereference in driver_nl80211.c if SME was in user space. Fix
this by passing the own MAC address in the sta_deauth call.
Signed-hostap: Jouni Malinen <j@w1.fi>