ASoC: hisilicon: Use the defined variable to clean code

Use the defined variable "dev" to make the code cleaner.

Signed-off-by: Zhang Shengju <zhangshengju@cmss.chinamobile.com>
Signed-off-by: Tang Bin <tangbin@cmss.chinamobile.com>
Link: https://lore.kernel.org/r/20200427091520.12412-1-tangbin@cmss.chinamobile.com


Signed-off-by: Mark Brown <broonie@kernel.org>