This prevents a number of issues where devices are enumerated but not actually able to be opened, like https://github.com/libsdl-org/SDL/issues/5781.
We currently leave the devices open, allowing us to more easily do controller feature detection, protocol negotiation, detect dropped Bluetooth connections, etc. with the expectation that the application is likely to open the controllers shortly.
- CMD_CHARGE_STATE was checking the seqnum instead of the payload
- Off-by-one error in size validation for command payload
- Unused payload space was left uninitialized in output report
