I don't now about the later versions of the standard but in C89, using the old style meant you did NOT get the type checking of the prototype style declarations. If there is no semantic difference these days, then yes, that would be a solution. I'm on the road and don't have the C11 standard handy, so I'll check later what the deal is.
The K&R style variable declarations are still also part of ANSI C, so you could write: