ACPI: fan: Delete the strict check in power transition

On some laptops the Fan device is turned on/off by controlling the
corresponding power resource. For example: If the power resource
defined in _PR0 object is turned off, it indicates that the FAN device
is in off state(the ACPI state is in D3 state).

Maybe the device is already in D3 state and expected to be transited to
D3 state. As there is no _PR3 object, the power transition can't be
finished and it will be switched to the Unknown state.

Maybe it is more reasonable that the strick check in power transistion
is deleted.

http://bugzilla.kernel.org/show_bug.cgi?id=9485

Signed-off-by:  <yakui.zhao@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>