Fix used_space_insert() to correctly service an empty used_space B+tree.
tree797f92243e0e5125d0246c8d0639b5243469c3d2
-rw-r--r-- 8319 Makefile
drwxr-xr-x - arch
drwxr-xr-x - contrib
drwxr-xr-x - doc
drwxr-xr-x - genarch
drwxr-xr-x - generic
-rw-r--r-- 3612 kernel.config
drwxr-xr-x - test
drwxr-xr-x - tools