ACPI: scan: Define acpi_bus_put_acpi_device() as static inline

Since acpi_bus_put_acpi_device() is a synonym for acpi_dev_put(),
define it as static inline in analogy with the latter.

No functional impact.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>