ACPI / Thermal / video: fix max_level incorrect value

commit 05950094 (ACPI/video: export acpi_video_get_levels)
mistakenly dropped the correct value of max_level and that caused the
set_level function following failed and the acpi_video backlight interface
didn't get created. Fix this by passing back the correct max_level value.

While at it, also fix the param used in acpi_video_device_lcd_query_levels
where acpi_handle is expected but acpi_video_device is passed.

Fixes: 05950094

 (ACPI/video: export acpi_video_get_levels)
Reported-and-tested-by: Valdis Kletnieks <valdis.kletnieks@vt.edu>
Signed-off-by: Aaron Lu <aaron.lu@intel.com>
Acked-by: Zhang Rui <rui.zhang@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>