iwlwifi: fix resart flow after fw error

Clear STATUS_FW_ERROR in the _up_ flow before reseting NIC.
UP flow will otherwise call restart again causing endless restart loop.

Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>
Signed-off-by: Tomas Winkler <tomas.winkler@intel.com>
Signed-off-by: Zhu Yi <yi.zhu@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>