ASoC: Get correct revision id for wm2200

Signed-off-by: NAxel Lin <axel.lin@gmail.com>
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>

sound/soc/codecs/wm2200.c

@@ -2084,7 +2084,7 @@ static __devinit int wm2200_i2c_probe(struct i2c_client *i2c,
 		goto err_reset;
 	}
 
-	wm2200->rev = ret & WM2200_DEVICE_REVISION_MASK;
+	wm2200->rev = reg & WM2200_DEVICE_REVISION_MASK;
 
 	dev_info(&i2c->dev, "revision %c\n", wm2200->rev + 'A');