e1000e: fix stats locking in e1000_watchdog_task

Just move the unlock down a bit because it unlocks too
early leaving a chance for get_stats64() run in parallel
while it is still accessing the stats.
Signed-off-by: Flavio Leitner <fleitner@redhat.com>
Acked-by: Bruce Allan <bruce.w.allan@intel.com>
Tested-by: Aaron Brown <aaron.f.brown@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

drivers/net/e1000e/netdev.c

@@ -4339,7 +4339,6 @@ static void e1000_watchdog_task(struct work_struct *work)
 link_up:
 	spin_lock(&adapter->stats64_lock);
 	e1000e_update_stats(adapter);
-	spin_unlock(&adapter->stats64_lock);
 
 	mac->tx_packet_delta = adapter->stats.tpt - adapter->tpt_old;
 	adapter->tpt_old = adapter->stats.tpt;
@@ -4350,6 +4349,7 @@ static void e1000_watchdog_task(struct work_struct *work)
 	adapter->gorc_old = adapter->stats.gorc;
 	adapter->gotc = adapter->stats.gotc - adapter->gotc_old;
 	adapter->gotc_old = adapter->stats.gotc;
+	spin_unlock(&adapter->stats64_lock);
 
 	e1000e_update_adaptive(&adapter->hw);