[PATCH] ALSA: Fix Oops of suspend/resume with generic drivers

The patch fixes Oops from sound drivers using generic platform device
but have no suspend/resume callbacks.

Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/sound/core/init.c b/sound/core/init.c
index a570201..c72a791 100644
--- a/sound/core/init.c
+++ b/sound/core/init.c
@@ -828,7 +828,8 @@
 	card = get_snd_generic_card(dev);
 	if (card->power_state == SNDRV_CTL_POWER_D3hot)
 		return 0;
-	card->pm_suspend(card, PMSG_SUSPEND);
+	if (card->pm_suspend)
+		card->pm_suspend(card, PMSG_SUSPEND);
 	snd_power_change_state(card, SNDRV_CTL_POWER_D3hot);
 	return 0;
 }
@@ -843,7 +844,8 @@
 	card = get_snd_generic_card(dev);
 	if (card->power_state == SNDRV_CTL_POWER_D0)
 		return 0;
-	card->pm_resume(card);
+	if (card->pm_suspend)
+		card->pm_resume(card);
 	snd_power_change_state(card, SNDRV_CTL_POWER_D0);
 	return 0;
 }