Solve minor bug in baccktracing unix.
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
-#ifdef(defined(__APPLE__) && defined(__MACH__)) || defined(__MACOSX__)
+#if (defined(__APPLE__) && defined(__MACH__)) || defined(__MACOSX__)
#include <sys/ucontext.h>
#else
#include <ucontext.h>
