fix(epicardium): volatile API_CALL_MEM->int_id to avoid infinite loop

...otherwise ->int_id will not be reloaded in the while-loop at api_interrupt_trigger(), causing it to loop indefinitely

Looks good to me! Thanks for keeping our codebase clean.

However, I'm only a bot - so a human will still have to approve this request.

merged

mentioned in commit 4f101232