ASoC: Add missing __devexit in wm8940.c

Signed-off-by: Takashi Iwai <tiwai@suse.de>
diff --git a/sound/soc/codecs/wm8940.c b/sound/soc/codecs/wm8940.c
index a66dacc..b8e17d6 100644
--- a/sound/soc/codecs/wm8940.c
+++ b/sound/soc/codecs/wm8940.c
@@ -907,7 +907,7 @@
 	return wm8940_register(wm8940);
 }
 
-static int wm8940_i2c_remove(struct i2c_client *client)
+static int __devexit wm8940_i2c_remove(struct i2c_client *client)
 {
 	struct wm8940_priv *wm8940 = i2c_get_clientdata(client);