patch to un-K&R-ify libkern

[David Cuthbert]

Joerg Sonnenberger wrote:
Commited. Thanks. The addition of (void) to empty_loop() and co
is unnecessary.
?

In C (but not C++), "void empty_loop()" is a function taking any number 
of args, equivalent to "void empty_loop(...)"; the (void) addition 
prohibits arguments from being passed.  Presumably, this matches a 
header somewhere?  (Though I didn't see it in the patch.)