ASoC: max98090: remove useless assignment

cppcheck warning:

sound/soc/codecs/max98090.c:1835:16: style: Variable 'test_diff' is
assigned a value that is never used. [unreadVariable]
 int test_diff = INT_MAX;
               ^
Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Link: https://lore.kernel.org/r/20210312182246.5153-13-pierre-louis.bossart@linux.intel.comSigned-off-by: Mark Brown <broonie@kernel.org>

sound/soc/codecs/max98090.c

@@ -1832,7 +1832,7 @@ static const struct dmic_table dmic_table[] = { /* One for each pclk freq. */
 static int max98090_find_divisor(int target_freq, int pclk)
 {
 	int current_diff = INT_MAX;
-	int test_diff = INT_MAX;
+	int test_diff;
 	int divisor_index = 0;
 	int i;