str: change example to match function being explained.
[ccan] / ccan / rbtree /
drwxr-xr-x   ..
lrwxrwxrwx 20 LICENSE -> ../../licenses/GPL-3
-rw-r--r-- 3120 _info
-rw-r--r-- 21776 rbtree.c
-rw-r--r-- 3153 rbtree.h
drwxr-xr-x - test