Make flush_tlb_all_local take a void * so it doesn't have to be cast
when using on_each_cpu().  This becomes a problem when on_each_cpu
is a macro.

Also remove the prototype of flush_tlb_all_local from .c files.
Signed-off-by: Matthew Wilcox <willy@parisc-linux.org>
Signed-off-by: Kyle McMartin <kyle@parisc-linux.org>