cpufreq: s3c64xx: Remove pointless NULL check in s3c64xx_cpufreq_driver_init

When building with Clang + -Wtautological-pointer-compare:

drivers/cpufreq/s3c64xx-cpufreq.c:152:6: warning: comparison of array
's3c64xx_freq_table' equal to a null pointer is always false
[-Wtautological-pointer-compare]
        if (s3c64xx_freq_table == NULL) {
            ^~~~~~~~~~~~~~~~~~    ~~~~
1 warning generated.

The definition of s3c64xx_freq_table is surrounded by an ifdef
directive for CONFIG_CPU_S3C6410, which is always true for this driver
because it depends on it in drivers/cpufreq/Kconfig.arm (and if it
weren't, there would be a build error because s3c64xx_freq_table would
not be a defined symbol).

Resolve this warning by removing the unnecessary NULL check because it
is always false as Clang notes. While we are at it, remove the
unnecessary ifdef conditional because it is always true.

Fixes: b3748ddd ("[ARM] S3C64XX: Initial support for DVFS")
Link: https://github.com/ClangBuiltLinux/linux/issues/748


Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>