Staging: batman-adv: Remove NULL pointer check

It is safe to call kfree(NULL) which makes this extra check unneeded. It
was found using checkpatch.pl from linux-2.6

Signed-off-by: Sven Eckelmann <sven.eckelmann@gmx.de>
Acked-by: Simon Wunderlich <siwu@hrz.tu-chemnitz.de>
Signed-off-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

drivers/staging/batman-adv/hard-interface.c

@@ -399,8 +399,7 @@ int hardif_add_interface(char *dev, int if_num)
 	return 1;
 
 out:
-	if (batman_if->packet_buff)
-		kfree(batman_if->packet_buff);
+	kfree(batman_if->packet_buff);
 	kfree(batman_if);
 	kfree(dev);
 	return -1;