wifi: wilc1000: set correct value of 'close' variable in failure case

Set 'close' variable to '1' to indicate closing operation when
initialisation fails during wlan_initialize_threads() call.

Signed-off-by: Ajay Singh <ajay.kathat@microchip.com>
Signed-off-by: Kalle Valo <kvalo@kernel.org>
Link: https://lore.kernel.org/r/20220720160302.231516-3-ajay.kathat@microchip.com