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

scripts/checkpatch.pl

@@ -2665,6 +2665,15 @@ sub process {
 				$herecurr);
                }
 
+# check for function declarations without arguments like "int foo()"
+		if ($line =~ /(\b$Type\s+$Ident)\s*\(\s*\)/) {
+			if (ERROR("FUNCTION_WITHOUT_ARGS",
+				  "Bad function definition - $1() should probably be $1(void)\n" . $herecurr) &&
+			    $fix) {
+				$fixed[$linenr - 1] =~ s/(\b($Type)\s+($Ident))\s*\(\s*\)/$2 $3(void)/;
+			}
+		}
+
 # check for uses of DEFINE_PCI_DEVICE_TABLE
 		if ($line =~ /\bDEFINE_PCI_DEVICE_TABLE\s*\(\s*(\w+)\s*\)\s*=/) {
 			if (WARN("DEFINE_PCI_DEVICE_TABLE",