ACPI battery: update status upon sysfs query

Sometimes the Battery driver doesn't get notifications when it's
plugged/unplugged. And this results in the incorrect Battery
status reported by the power supply sysfs I/F.

Update Battery status first when querying from sysfs.
http://marc.info/?l=linux-acpi&m=128855015826728&w=2



Tested_by: Seblu <seblu@seblu.net>
Signed-off-by: Zhang Rui <rui.zhang@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>