iwlwifi: dvm: don't send HCMD in restart flow

iwlwifi: dvm: don't send HCMD in restart flow

commit 2d5d50ee596361566f7f84300117cba7d7672bc5 upstream.

There is a race between the restart flow and the workers.
The workers are cancelled after the fw is already killed
and might send HCMD when there is fw to handle them.
Simply check that there is a fw to which the HCMD can be
sent before actually sending it.

Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Lingzhu Xiang <lxiang@redhat.com>
Reviewed-by: CAI Qian <caiqian@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>