LU-9704 grant: ignore grant info on read resend

LU-9704 grant: ignore grant info on read resend

The following scenario makes a message like "claims 28672 GRANT, real
grant 0" to appear:

 1. client owns X grants and run rpcs to shrink part of those
 2. server fails over so that the shrink rpc is to be resent.
 3. on the clinet reconnect server and client sync on initial amount
 of grants for the client.
 4. shrink rpc is resend, if server disk space is enough, shrink does
 not happen and the client adds amount of grants it was going to
 shrink to its newly initial amount of grants. Now, client thinks that
 it owns more grants than it does from server points of view.
 5. the client consumes grants and sends rpcs to server. Server avoids
 allocating new grants for the client if the current amount of grant
 is big enough:
static long tgt_grant_alloc(struct obd_export *exp, u64 curgrant,
...
        if (curgrant >= want || curgrant >= ted->ted_grant + chunk)
                RETURN(0);
 6. client continues grants consuming which eventually leads to
 complains like "claims 28672 GRANT, real grant 0".

In case of resent of read and set_info:shrink RPCs grant info should
be ignored as it was reset on reconnect.

Tests to illustrate the issue is added.

HPE-bug-id: LUS-7666
Change-Id: I8af1db287dc61c713e5439f4cf6bd652ce02c12c
Signed-off-by: Vladimir Saveliev <vlaidimir.saveliev@hpe.com>
Reviewed-on: https://review.whamcloud.com/45371
Reviewed-by: Andreas Dilger <adilger@whamcloud.com>
Tested-by: jenkins <devops@whamcloud.com>
Tested-by: Maloo <maloo@whamcloud.com>
Reviewed-by: Mike Pershin <mpershin@whamcloud.com>
Reviewed-by: Oleg Drokin <green@whamcloud.com>