iwlwifi: mvm: use schedule_delayed_work()

There's no need to refer to system_wq directly, use the provided
wrapper schedule_delayed_work().

Made with the following spatch:
    @@
    expression E,F;
    @@
    -queue_delayed_work(system_wq, E, F);
    +schedule_delayed_work(E, F);

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>
diff --git a/drivers/net/wireless/intel/iwlwifi/mvm/fw-dbg.c b/drivers/net/wireless/intel/iwlwifi/mvm/fw-dbg.c
index aac0426..a8353ea1 100644
--- a/drivers/net/wireless/intel/iwlwifi/mvm/fw-dbg.c
+++ b/drivers/net/wireless/intel/iwlwifi/mvm/fw-dbg.c
@@ -927,7 +927,7 @@ int iwl_mvm_fw_dbg_collect_desc(struct iwl_mvm *mvm,
 	mvm->fw_dump_desc = desc;
 	mvm->fw_dump_trig = trigger;
 
-	queue_delayed_work(system_wq, &mvm->fw_dump_wk, delay);
+	schedule_delayed_work(&mvm->fw_dump_wk, delay);
 
 	return 0;
 }