NFSv4: Fix clearing of layout segments in layoutreturn

[ Upstream commit d72b7963 ]

Make sure that we clear the layout segments in cases where we see a
fatal error, and also in the case where the layout is invalid.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>