message: remove obsolete return type
diff: @@ -591,7 +591,7 @@ static void show_registers(int id, struct kvm_regs* regs, struct kvm_sregs* sreg
  fprintf(stderr, "\n");
  }
  -static int print_registers(void)
  +static void print_registers(void)
  {
  struct kvm_regs regs;
  struct kvm_sregs sregs;
  