staging: wilc1000: remove unnecessary static variable 'p2p_listen_state'

Remove the use of unnecessary static variable 'p2p_listen_state'.
Already 'p2p_listen_state' is present in 'wilc_priv' struct. So making
use of that variable as its getting set in channel ready and
remain on channel expired callback.

Signed-off-by: Ajay Singh <ajay.kathat@microchip.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>