kclient: fix inode refcount problems in ceph_fill_trace
kclient: fix inode refcount problems in ceph_fill_trace

If we fail to take i_mutex, we get the inode via ceph_get_inode, which bumps
i_count.  Make sure we iput() it before jumping to update_inode label.  Note
that d_instantiate consumes the ref, but the other paths (d_alloc_anon,
d_find_alias) do not.

ajnelson/ceph,ajnelson/ceph,ajnelson/ceph,ajnelson/ceph,ajnelson/ceph,ajnelson/ceph