iwlwifi: mvm: protect RCU dereference in iwl_mvm_get_key_sta_id
Properly protect the RCU dereference in iwl_mvm_get_key_sta_id() when
coming from iwl_mvm_update_tkip_key() which cannot hold the mvm->mutex
by moving the call into the RCU critical section.
Modify the check to use rcu_dereference_check() to permit this.
Fixes: 9513c5e18a0d ("iwlwifi: mvm: Avoid dereferencing sta if it was already flushed") Reported-by: Laura Abbott <labbott@redhat.com> Signed-off-by: Johannes Berg <johannes.berg@intel.com> Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>