P2P: Clear pending_listen_freq when starting GO Neg/Invite

P2P: Clear pending_listen_freq when starting GO Neg/Invite

Previously, it was possible for the p2p->pending_listen_freq to be left
at non-zero value if Probe Request frame was received from a peer with
which we were waiting to start GO Negotiation/Invite process. That could
result in the following Listen operation getting blocked in some
operation sequences if the peer did not acknowledge the following P2P
Public Action frame.

Signed-off-by: Jouni Malinen <j@w1.fi>