sysctl: use stdbool.h

The stdbool.h header is part of C99 and has been usable on systems for
more than a decade.  Let's drop these manual hacks.

Signed-off-by: Mike Frysinger <vapier@gentoo.org>

sysctl.c

@@ -32,6 +32,7 @@
 #include <libgen.h>
 #include <limits.h>
 #include <regex.h>
+#include <stdbool.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
@@ -46,11 +47,6 @@
 #include "proc/procps.h"
 #include "proc/version.h"
 
-/* Proof that C++ causes brain damage: */
-typedef int bool;
-static bool true  = 1;
-static bool false = 0;
-
 /*
  *    Globals...
  */