soc: samsung: s3c-pm-check: Fix incorrectly named variable 'val'

soc: samsung: s3c-pm-check: Fix incorrectly named variable 'val'

Fixes the following W=1 kernel build warning(s):

 drivers/soc/samsung/s3c-pm-check.c:162: warning: Function parameter or member 'val' not described in 's3c_pm_runcheck'
 drivers/soc/samsung/s3c-pm-check.c:162: warning: Excess function parameter 'vak' description in 's3c_pm_runcheck'

Signed-off-by: Lee Jones <lee.jones@linaro.org>
Cc: Ben Dooks <ben@simtec.co.uk>
Link: https://lore.kernel.org/r/20201103152838.1290217-15-lee.jones@linaro.org
Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>