acpi_device_set_power() prints debug messages regarding its outcome
(whether or not the power state has been changed and how) in all
cases except when the device whose power state is being changed to D0
is in that power state already.

Make acpi_device_set_power() print a final debug message in that case
too and while at it, fix the indentation of the "end" label in this
function.
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>