wil6210: fix interface-up check

While wil_open is executed, any call to netif_running
would return a success. In case there are failures
within wil_open, should not treat the device as if it
is already opened in relevant functions (like FW recovery
and runtime suspend check).

Fix that by checking the device up flag instead.

Signed-off-by: Hamad Kadmany <qca_hkadmany@qca.qualcomm.com>
Signed-off-by: Maya Erez <qca_merez@qca.qualcomm.com>
Signed-off-by: Kalle Valo <kvalo@qca.qualcomm.com>