xfsprogs: fix inode crash in xfs_repair

xfsprogs: fix inode crash in xfs_repair

Adding the lost+found in phase 6 could allocate an inode from
a new inode chunk. Since this chunk was not around in phase 3
when the inode chunks are verificated and added to the avl tree,
the avl tree look up will return a NULL pointer. This results
in a NULL defererence and segmentation fault.

Add the newly created inode chunk as if found in the chunk
verification phase.

Signed-off-by: Mark Tinguely <tinguely@sgi.com>
Reviewed-by: Rich Johnston <rjohnston@sgi.com>
Signed-off-by: Rich Johnston <rjohnston@sgi.com>