[PATCH] nvme: Use NN for max_namespaces if MNAN is zero

[Sagi Grimberg]

>> Forgot to mention: During testing dynamically adding namespaces it was
>> possible to trigger the WARNINGs in the nvme_parse_ana_log(). Initially
>> the subsystem started with 8 namespaces and during runtime another 8
>> namespaces was added.
> 
> The controller is required to have a non-zero MNAN value if it supports
> ANA:
> 
>    If the controller supports Asymmetric Namespace Access Reporting, then
>    this field shall be set to a non-zero value that is less than or equal
>    to the NN value.

That was my thought exactly