batman-adv: iv_ogm, fix comment function name

This is a small copy paste fix for batadv_ing_buffer_avg.
Signed-off-by: Markus Pargmann <mpa@pengutronix.de>
Signed-off-by: Marek Lindner <mareklindner@neomailbox.ch>

net/batman-adv/bat_iv_ogm.c

@@ -55,7 +55,7 @@ static void batadv_ring_buffer_set(uint8_t lq_recv[], uint8_t *lq_index,
 }
 
 /**
- * batadv_ring_buffer_set - compute the average of all non-zero values stored
+ * batadv_ring_buffer_avg - compute the average of all non-zero values stored
  * in the given ring buffer
  * @lq_recv: pointer to the ring buffer
  *