ASoC: fixes to caching implementations

This patch takes fixes a number of bugs in the caching code used by
several ASoC codec drivers. Mostly off-by-one fixes.

Signed-off-by: Ian Molton <ian@mnementh.co.uk>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
diff --git a/sound/soc/codecs/wm8753.c b/sound/soc/codecs/wm8753.c
index 7283178..5a1c1fc 100644
--- a/sound/soc/codecs/wm8753.c
+++ b/sound/soc/codecs/wm8753.c
@@ -97,7 +97,7 @@
 	unsigned int reg)
 {
 	u16 *cache = codec->reg_cache;
-	if (reg < 1 || reg > (ARRAY_SIZE(wm8753_reg) + 1))
+	if (reg < 1 || reg >= (ARRAY_SIZE(wm8753_reg) + 1))
 		return -1;
 	return cache[reg - 1];
 }
@@ -109,7 +109,7 @@
 	unsigned int reg, unsigned int value)
 {
 	u16 *cache = codec->reg_cache;
-	if (reg < 1 || reg > 0x3f)
+	if (reg < 1 || reg >= (ARRAY_SIZE(wm8753_reg) + 1))
 		return;
 	cache[reg - 1] = value;
 }