device-drivers/acpi/ltp_acpi_cpufreq: fix checking for write permission

If access(some_file, W_OK) is executed by root it will return success even
if file has read-only permission. Use 'open' to test sysfs file for write
permission.

Signed-off-by: Alexey Kodanev <alexey.kodanev@oracle.com>
1 file changed