ALSA: hda - Fix unbalanced runtime PM refcount after S3/S4

When a machine goes to S3/S4 after power-save is enabled, the runtime
PM refcount might be incorrectly decreased because the power-down
triggered soon after resume assumes that the controller was already
powered up, and issues the pm_notify down.

This patch fixes the incorrect pm_notify call simply by checking the
current value properly.

Cc: <stable@vger.kernel.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

sound/pci/hda/hda_codec.c

@@ -4864,8 +4864,8 @@ static void hda_power_work(struct work_struct *work)
 	spin_unlock(&codec->power_lock);
 
 	state = hda_call_codec_suspend(codec, true);
-	codec->pm_down_notified = 0;
-	if (!bus->power_keep_link_on && (state & AC_PWRST_CLK_STOP_OK)) {
+	if (!codec->pm_down_notified &&
+	    !bus->power_keep_link_on && (state & AC_PWRST_CLK_STOP_OK)) {
 		codec->pm_down_notified = 1;
 		hda_call_pm_notify(bus, false);
 	}