IF NFS_LAYOUT_RETURN_REQUESTED is not set, then we currently exit
without freeing the list of invalidated layout segments, leading
to a reference leak.
Reported-by: NOlga Kornievskaia <aglo@umich.edu>
Fixes: 24408f52 ("pNFS: Fix bugs in _pnfs_return_layout")
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>