fs: reference-count inodes, fix generic loadconfig

fs: reference-count inodes, fix generic loadconfig

Reference-count inodes, so we don't leak them all over the place.
This also lets us hold onto the root inode from the very beginning.
Make the generic loadconfig work again.  Significant cleanups to the
ext2 filesystem core.

Signed-off-by: H. Peter Anvin <hpa@zytor.com>