'obj' is being initialized, however this value is never read as
'obj' is assigned an updated value later. Remove the redundant
initialization.

Clean up clang warning:
drivers/acpi/processor_throttling.c:409:20: warning: Value stored to
'obj' during its initialization is never read
[clang-analyzer-deadcode.DeadStores]
Reported-by: Abaci Robot <abaci@linux.alibaba.com>
Signed-off-by: Yang Li <yang.lee@linux.alibaba.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>