P2P: Fix P2P_FIND while waiting for listen ROC to start in the driver

P2P: Fix P2P_FIND while waiting for listen ROC to start in the driver

It was possible for the p2p->pending_listen_freq to be left indicating
that there is a pending ROC for a listen operation if a P2P_FIND command
was timed to arrive suitably between a previous Listen operation issuing
a ROC request and the kernel code starting that request. This could
result in the P2P state machine getting stuck unable to continue the
find ("P2P: p2p_listen command pending already").

Fix this by clearing p2p->pending_listen_freq when starting P2P_FIND
command execution.

Signed-off-by: Jouni Malinen <jouni@qca.qualcomm.com>