ALSA: cmi8330: fix MPU-401 PnP init copy&paste bug

Fix copy&paste bug in PnP MPU-401 initialization.

Signed-off-by: Ondrej Zary <linux@rainbow-software.org>
Cc: <stable@kernel.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
diff --git a/sound/isa/cmi8330.c b/sound/isa/cmi8330.c
index de83608..3ee0269 100644
--- a/sound/isa/cmi8330.c
+++ b/sound/isa/cmi8330.c
@@ -338,7 +338,7 @@
 		return -EBUSY;
 
 	acard->mpu = pnp_request_card_device(card, id->devs[2].id, NULL);
-	if (acard->play == NULL)
+	if (acard->mpu == NULL)
 		return -EBUSY;
 
 	pdev = acard->cap;