cpufreq: ACPI: Remove unused variables 'acpi_cpufreq_online' and 'ret'

Clang warns:

  drivers/cpufreq/acpi-cpufreq.c:970:24: error: variable 'ret' is uninitialized when used here [-Werror,-Wuninitialized]
          acpi_cpufreq_online = ret;
                                ^~~
  drivers/cpufreq/acpi-cpufreq.c:960:9: note: initialize the variable 'ret' to silence this warning
          int ret;
                ^
                  = 0
  1 error generated.

Both ret and acpi_cpufreq_online are now unused so they can be safely
removed, clearing up the warning.

Fixes: 13fdbc8b ("cpufreq: ACPI: Defer setting boost MSRs")
Link: https://github.com/ClangBuiltLinux/linux/issues/1757


Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>