fix compile error

git-svn-id: https://rt-thread.googlecode.com/svn/trunk@1081 bbd45198-f89e-11dd-88c7-29a3b14d5316

components/libdl/dlfcn.h

@@ -14,3 +14,5 @@ void *dlopen (const char *filename, int flag);
 const char *dlerror(void);
 void *dlsym(void *handle, const char *symbol);
 int dlclose (void *handle);
+
+#endif