commit 2240a9e2 upstream.

If we do not release the sequence id in cases where we fail to get a
session slot, then we can deadlock if we hit a recovery scenario.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
[bwh: Backported to 3.2:
 - Adjust context
 - nfs4_setup_sequence() has an additional 'cache_reply' parameter]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>