iwlwifi: mvm: flush fw_dump_wk when mvm fails to start

iwlwifi: mvm: flush fw_dump_wk when mvm fails to start

commit dbf73d4a8bb8f4e1d1f3edd3be825692279e2ef3 upstream.

FW dump may be triggered when running init ucode, for example due to a
sysassert. In this case fw_dump_wk may run after mvm is freed, resulting
in a kernel panic.
Fix it by flushing the work.

Fixes: 01b988a708af ("iwlwifi: mvm: allow to collect debug data when restart is disabled")
Signed-off-by: Andrei Otcheretianski <andrei.otcheretianski@intel.com>
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>