patch to un-K&R-ify libkern

[Joerg Sonnenberger]

After another discussion with Jeroen on IRC and some more spec reading
I want to give the following summary:
- int A() {return 0;} is valid ISO C99 and specifies a function without
  specifying a prototype. Therefore the e.g. the argument passing is _not_
  enforced by the compiler. Although it is my believe that this is stupid.
- int A(void) {return 0;} is a valid definition and protype for A. This
  means correct enforcement of the number of arguments.

Now I confess that I was wrong and the style(9) change is correct.

Joerg