When a function returns void, it can be used as an argument to return in
function returning also void, e.g.:
void in(void) {
return;
}
void out(void) {
return (in());
}
while this is legal, it should be rewritten as:
void out(void) {
in();
return;
}
The semantic patch just find the occurrences, and they need to be fixed
by hand.