Use limits.h instead of syslimits.h

Regression found by tinderbox in 89b3485dad

xcb_util.c:31:27: error: sys/syslimits.h: No such file or directory
xcb_util.c: In function '_xcb_open':
xcb_util.c:148: error: 'PATH_MAX' undeclared (first use in this function)

Signed-off-by: Jeremy Huddleston <jeremyhu@apple.com>

src/xcb_util.c

@@ -28,7 +28,7 @@
 #include <assert.h>
 #include <sys/types.h>
 #include <sys/socket.h>
-#include <sys/syslimits.h>
+#include <limits.h>
 #include <sys/un.h>
 #include <netinet/in.h>
 #include <netinet/tcp.h>