ALSA: PCI: Remove superfluous pci_set_drvdata(pci, NULL) at remove

As drvdata is cleared to NULL at probe failure or at removal by the
driver core, we don't have to call pci_set_drvdata(pci, NULL) any
longer in each driver.

The only remaining pci_set_drvdata(NULL) is in azx_firmware_cb() in
hda_intel.c.  Since this function itself releases the card instance,
we need to clear drvdata here as well, so that it won't be released
doubly in the remove callback.

Signed-off-by: Takashi Iwai <tiwai@suse.de>

sound/pci/pcxhr/pcxhr.c

@@ -1691,7 +1691,6 @@ static int pcxhr_probe(struct pci_dev *pci,
 static void pcxhr_remove(struct pci_dev *pci)
 {
 	pcxhr_free(pci_get_drvdata(pci));
-	pci_set_drvdata(pci, NULL);
 }
 
 static struct pci_driver pcxhr_driver = {