fix parameter type for signal handler
The on_prompter_prompting signal handler used a struct as a otherwise unused parameter while a pointer was passed by the caller. This led to a stack smashing on the ppc64le platform and a segfault.
The on_prompter_prompting signal handler used a struct as a otherwise unused parameter while a pointer was passed by the caller. This led to a stack smashing on the ppc64le platform and a segfault.