stringmap: fail path can print uninitialized var in test.
[ccan] / ccan / stringmap /
drwxr-xr-x   ..
-rw-r--r-- 3634 _info
-rw-r--r-- 9322 stringmap.c
-rw-r--r-- 3219 stringmap.h
drwxr-xr-x - test