libcli/smb: allow unexpected padding in SMB2 READ responses

libcli/smb: allow unexpected padding in SMB2 READ responses

Make use of smb2cli_parse_dyn_buffer() in smb2cli_read_done()
as it was exactly introduced for a similar problem see:

    commit 4c6c71e1378401d66bf2ed230544a75f7b04376f
    Author:     Stefan Metzmacher <metze@samba.org>
    AuthorDate: Thu Jan 14 17:32:15 2021 +0100
    Commit:     Volker Lendecke <vl@samba.org>
    CommitDate: Fri Jan 15 08:36:34 2021 +0000

        libcli/smb: allow unexpected padding in SMB2 IOCTL responses

        A NetApp Ontap 7.3.7 SMB server add 8 padding bytes to an
        offset that's already 8 byte aligned.

        RN: Work around special SMB2 IOCTL response behavior of NetApp Ontap 7.3.7
        BUG: https://bugzilla.samba.org/show_bug.cgi?id=14607

        Pair-Programmed-With: Volker Lendecke <vl@samba.org>

        Signed-off-by: Stefan Metzmacher <metze@samba.org>
        Signed-off-by: Volker Lendecke <vl@samba.org>
        Autobuild-User(master): Volker Lendecke <vl@samba.org>
        Autobuild-Date(master): Fri Jan 15 08:36:34 UTC 2021 on sn-devel-184

RN: Work around special SMB2 READ response behavior of NetApp Ontap 7.3.7
BUG: https://bugzilla.samba.org/show_bug.cgi?id=14607

Signed-off-by: Stefan Metzmacher <metze@samba.org>
Reviewed-by: Jeremy Allison <jra@samba.org>
Autobuild-User(master): Jeremy Allison <jra@samba.org>
Autobuild-Date(master): Thu Jul 15 23:53:55 UTC 2021 on sn-devel-184

(cherry picked from commit 155348cda65b441a6c4db1ed84dbf1682d02973c)