str: clean up tests so ccanlint doesn't complain about memory leaking.
[ccan] / ccan / str /
drwxr-xr-x   ..
lrwxrwxrwx 23 LICENSE -> ../../licenses/LGPL-2.1
-rw-r--r-- 806 _info
-rw-r--r-- 1447 str.h
drwxr-xr-x - test