Commit 
3d5b6fb47a8e68fa311ca2c3447e7f8a7c3a9cf3 ("ACPI: Kill overly
verbose "power state" log messages") removed the actual use of this
variable, but didn't remove the variable itself, resulting in build
warnings like
  drivers/acpi/processor_idle.c: In function ‘acpi_processor_power_init’:
  drivers/acpi/processor_idle.c:1169: warning: unused variable ‘i’
Just get rid of the now unused variable.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
 
 #ifdef CONFIG_ACPI_PROCFS
        struct proc_dir_entry *entry = NULL;
 #endif
-       unsigned int i;
 
        if (boot_option_idle_override)
                return 0;