batman-adv: Use parentheses in function kernel-doc

The documentation describing kernel-doc comments for functions ("How to
format kernel-doc comments") uses parentheses at the end of the function
name. Using this format allows to use a consistent style when adding
documentation to a function and when referencing this function in a
different kernel-doc section.

Signed-off-by: Sven Eckelmann <sven@narfation.org>
Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de>
diff --git a/net/batman-adv/bitarray.h b/net/batman-adv/bitarray.h
index 8cb2c87..0508353 100644
--- a/net/batman-adv/bitarray.h
+++ b/net/batman-adv/bitarray.h
@@ -27,7 +27,7 @@
 #include <linux/types.h>
 
 /**
- * batadv_test_bit - check if bit is set in the current window
+ * batadv_test_bit() - check if bit is set in the current window
  *
  * @seq_bits: pointer to the sequence number receive packet
  * @last_seqno: latest sequence number in seq_bits