[RFC PATCH] nvmet-tcp: Don't kmap() pages which can't come from HIGHMEM

[Sagi Grimberg]

>>> You should also remove the cmd's 'nr_mapped' field while you're at it,
>>> otherwise you'll hit the WARN in nvmet_tcp_free_cmd_buffers().
>>
>> Not remove nr_mapped because we use it to know the iovec entries, but
>> we can just remove the WARN statement.
> 
> It's only used locally within nvmet_tcp_map_pdu_iovec() after this change, so
> no need to carry it in struct nvmet_tcp_cmd anymore.

You are right, we can kill it.