cifs: Fix SMB1 readv/writev callback in the same way as SMB2/3

cifs: Fix SMB1 readv/writev callback in the same way as SMB2/3

Port a number of SMB2/3 async readv/writev fixes to the SMB1 transport:

    commit a88d60903696c01de577558080ec4fc738a70475
    cifs: Don't advance the I/O iterator before terminating subrequest

    commit ce5291e56081730ec7d87bc9aa41f3de73ff3256
    cifs: Defer read completion

    commit 1da29f2c39b67b846b74205c81bf0ccd96d34727
    netfs, cifs: Fix handling of short DIO read

Fixes: 3ee1a1fc3981 ("cifs: Cut over to using netfslib")
Signed-off-by: David Howells <dhowells@redhat.com>
Reported-by: Steve French <stfrench@microsoft.com>
Reviewed-by: Paulo Alcantara <pc@manguebit.com>
cc: Jeff Layton <jlayton@kernel.org>
cc: linux-cifs@vger.kernel.org
cc: netfs@lists.linux.dev
cc: linux-fsdevel@vger.kernel.org
Signed-off-by: Steve French <stfrench@microsoft.com>