NFSv4: Fix memory and state leak in _nfs4_open_and_get_state

commit a974deee477af89411e0f80456bfb344ac433c98 upstream.

If we exit because the file access check failed, we currently
leak the struct nfs4_state. We need to attach it to the
open context before returning.

Fixes: 3efb9722 ("NFSv4: Refactor _nfs4_open_and_get_state..")
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>