checkpatch.pl: check for function declarations without arguments

Functions like this one are evil:

void foo()
{
	...
}

Because these functions allow variadic arguments without
checking the arguments at all.

Original patch by Richard Weinberger.

Signed-off-by: Joe Perches <joe@perches.com>
Cc: Richard Weinberger <richard@nod.at>
Cc: Borislav Petkov <bp@alien8.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>