[PATCH] nvme: don't set a virt_boundary unless needed

[Sagi Grimberg]

>> Exactly because its odd. Unless there is any benefit of using sgls in
>> admin commands lets not flag it per transport.
> 
> The other transports always and unconditionally use SGLs anyway.  With
> the virt boundary we're just adding extra checks to fail certain
> passthrough admin commands (the kernel will never generate those cases).

I just don't see the point of adding a per-transport flag. Either we
always enforce admin queue virt_boundary in the core because its not
important enough, or we always allow sgls and have pci set this flag
locally (given that only it has this quirk).