NFSv4.1 don't free interrupted slot on open

commit 0cb98abb upstream.

Allow the async rpc task for finish and update the open state if needed,
then free the slot. Otherwise, the async rpc unable to decode the reply.

Signed-off-by: Olga Kornievskaia <kolga@netapp.com>
Fixes: ae55e59d ("pnfs: Don't release the sequence slot...")
Cc: stable@vger.kernel.org # v4.18+
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>