ALSA: usb-audio: Correct document for snd_usb_endpoint_free_all()

The kerndoc comment for the new function snd_usb_endpoint_free_all()
had a typo wrt the argument name.  Fix it.

Fixes: 00272c61 ("ALSA: usb-audio: Avoid unnecessary interface re-setup")
Reported-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Cc: <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/20210205082837.6327-1-tiwai@suse.deSigned-off-by: Takashi Iwai <tiwai@suse.de>

sound/usb/endpoint.c

@@ -1451,7 +1451,7 @@ void snd_usb_endpoint_release(struct snd_usb_endpoint *ep)
 
 /**
  * snd_usb_endpoint_free_all: Free the resources of an snd_usb_endpoint
- * @card: The chip
+ * @chip: The chip
  *
  * This free all endpoints and those resources
  */