An error line in example code in readme.md

[luduoduo]

Hi,
I found there is an error line in the example code, that "void *" should be "void **",
rebind_symbols((struct rebinding[2]){{"close", my_close, (void *)&orig_close}, {"open", my_open, (void *)&orig_open}}, 2);

-->
rebind_symbols((struct rebinding[2]){{"close", my_close, (void **)&orig_close}, {"open", my_open, (void **)&orig_open}}, 2);

hope it would be useful for new comer.

[grp]

Nice find! Want to send a pull request and fix it?