Since commit 0edb555 ("platform: Make platform_driver::remove() return
void"), the original `platform_driver::remove()` function returned an
integer value, usually an error code. This made driver developers think
that errors were properly handled. However, the driver core does not
stop the device removal process based on the error code, so the error
code did not serve its intended purpose. Therefore, the return type was
changed to `void` to avoid potential issues.
Make the devicemodel example run successfully on Linux v6.11+.
Testing detail:
- Tested on Raspberry Pi 5B with Raspberry Pi OS (Debian 12, Linux
version 6.12.1-v8-16k+)
- Verified the devicemodel examples compile and load successfully
e3e11431fc