Ignore LIBUSB_ERROR_INTERRUPTED in handleEvents to avoid unnecessary log spam

[iamgkstack]

This PR updates the handleEvents loop to ignore harmless LIBUSB_ERROR_INTERRUPTED (EINTR) errors returned by libusb_handle_events_completed.

Background

LIBUSB_ERROR_INTERRUPTED occurs when a system call is interrupted by a signal. This is a normal and expected condition and not a fatal error. However, the current implementation logs this at every occurrence, which results in excessive log spam in long-running applications (e.g., daemons or agents using USB hotplug)

Example logs before this change:

2025/09/19 12:53:48 handle_events error: LIBUSB_ERROR_INTERRUPTED: System call interrupted (perhaps due to signal)
2025/09/19 13:00:48 handle_events error: LIBUSB_ERROR_INTERRUPTED: System call interrupted (perhaps due to signal)
...

Change

The fix adds a simple conditional check:

if errno := C.libusb_handle_events_completed(libCtx, nil); errno < 0 {
if ErrorCode(errno) == ErrorInterrupted {
// Ignore harmless EINTR instead of spamming logs
continue
}
log.Printf("handle_events error: %s", ErrorCode(errno))
}

Benefits

Keeps logs clean by ignoring expected EINTR interruptions.

All other error conditions continue to be logged normally.

Improves usability for production services without changing external behavior.