ALSA: Cleanup redundant tests on unsigned

The variables are unsigned so the test `>= 0' is always true,
the `< 0' test always fails. In these cases the other part of
the test catches wrapped values.

In dac_audio_write() there does not occur a test for wrapped
values, but the test appears redundant.

Signed-off-by: Roel Kluin <roel.kluin@gmail.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
diff --git a/sound/soc/codecs/tlv320aic23.c b/sound/soc/codecs/tlv320aic23.c
index 0b8dcb5..35606ae 100644
--- a/sound/soc/codecs/tlv320aic23.c
+++ b/sound/soc/codecs/tlv320aic23.c
@@ -85,7 +85,7 @@
 	 * of data into val
 	 */
 
-	if ((reg < 0 || reg > 9) && (reg != 15)) {
+	if (reg > 9 && reg != 15) {
 		printk(KERN_WARNING "%s Invalid register R%u\n", __func__, reg);
 		return -1;
 	}