ASoC: codecs: msm8916-wcd-analog: always true condition

ASoC: codecs: msm8916-wcd-analog: always true condition

Static checkers complain that unsigned int val is always >= 0.  The
context is that snd_soc_read() returns -1U on error.  This is harmless
because we're checking that CDC_A_MBHC_RESULT_1_BTN_RESULT_MASK is not
set, and it will always be set for -1U.  I could have just removed the
check against -1 but I preserved it because I thought it helped with
readability.

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Mark Brown <broonie@kernel.org>