in constructor in hook.c:

#define GOT_DLOPEN_ADDR 0x081be558
*(void **)GOT_DLOPEN_ADDR = eth_dlopen;

so change name of function dlopen to eth_dlopen

and remove:
if (orig_dlsym == NULL) {
		orig_dlsym = &dlsym;
		*((void *(**)(const char *, int))DLSYM_GOT) = (void *(*)(const char *, int)) &wrap_dlsym;
}