ALSA: ad1816a: Fix potential NULL pointer deref in snd_card_ad1816a_pnp()

Use pr_warn() instead of dev_warn() when 'pdev' is NULL to avoid a
potential NULL pointer dereference.

Cc: stable@vger.kernel.org
Fixes: 2086917 ("ALSA: ad1816a: Use standard print API")
Signed-off-by: Thorsten Blum <thorsten.blum@linux.dev>
Link: https://patch.msgid.link/20250703200616.304309-2-thorsten.blum@linux.dev
Signed-off-by: Takashi Iwai <tiwai@suse.de>

Author: toblux

sound/isa/ad1816a/ad1816a.c

@@ -98,7 +98,7 @@ static int snd_card_ad1816a_pnp(int dev, struct pnp_card_link *card,
 	pdev = pnp_request_card_device(card, id->devs[1].id, NULL);
 	if (pdev == NULL) {
 		mpu_port[dev] = -1;
-		dev_warn(&pdev->dev, "MPU401 device busy, skipping.\n");
+		pr_warn("MPU401 device busy, skipping.\n");
 		return 0;
 	}