NFSv4.1: Defer bumping the slot sequence number until we free the slot

NFSv4.1: Defer bumping the slot sequence number until we free the slot

For operations like OPEN or LAYOUTGET, which return recallable state
(i.e. delegations and layouts) we want to enable the mechanism for
resolving recall races in RFC5661 Section 2.10.6.3.
To do so, we will want to defer bumping the slot's sequence number until
we have finished processing the RPC results.

Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
(cherry picked from commit 07e8dcbda71ef87e9cbdc42b5bb16a44c1ab839b)

orabug: 25513155
Signed-off-by: Todd Vierling <todd.vierling@oracle.com>
Reviewed-By: Jack Vogel <jack.vogel@oracle.com>
Tested-by: xuan.qi@oracle.com
Signed-off-by: Manjunath Patil <manjunath.b.patil@oracle.com>