The val is defined as unsigned int type, if(val<0) is redundant, so
delete it.

sound/soc/codecs/idt821034.c:449 idt821034_kctrl_gain_put() warn: unsigned 'val' is never less than zero.
Reported-by: Abaci Robot <abaci@linux.alibaba.com>
Link: https://bugzilla.openanolis.cn/show_bug.cgi?id=3947Signed-off-by: Jiapeng Chong <jiapeng.chong@linux.alibaba.com>
Acked-by: Herve Codina <herve.codina@bootlin.com>
Link: https://lore.kernel.org/r/20230206075518.84169-1-jiapeng.chong@linux.alibaba.comSigned-off-by: Mark Brown <broonie@kernel.org>