batman-adv: fix kerneldoc for DAT functions

Signed-off-by: Antonio Quartulli <a@unstable.cc>

net/batman-adv/distributed-arp-table.c

@@ -741,6 +741,8 @@ static void batadv_dat_hash_free(struct batadv_priv *bat_priv)
 /**
  * batadv_dat_init - initialise the DAT internals
  * @bat_priv: the bat priv with all the soft interface information
+ *
+ * Return: 0 in case of success, a negative error code otherwise
  */
 int batadv_dat_init(struct batadv_priv *bat_priv)
 {
@@ -779,6 +781,8 @@ void batadv_dat_free(struct batadv_priv *bat_priv)
  * batadv_dat_cache_seq_print_text - print the local DAT hash table
  * @seq: seq file to print on
  * @offset: not used
+ *
+ * Return: always 0
  */
 int batadv_dat_cache_seq_print_text(struct seq_file *seq, void *offset)
 {