ACPI: processor: idle: Remove redundant pr->power.count assignment

ACPI: processor: idle: Remove redundant pr->power.count assignment

pr->power.count stands for the number of valid processor cstates. And it
is correctly set with the return value of acpi_processor_power_verify(),
in acpi_processor_get_cstate_info().

Remove the redundant logic that unnecessarily overrides pr->power.count
value.

No functional change intended.

Signed-off-by: Zhang Rui <rui.zhang@intel.com>
Link: https://patch.msgid.link/20250409005026.1932637-3-rui.zhang@intel.com
[ rjw: Removed unused variable, fixed up white space ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>