bhyve: Avoid unlikely truncation of the blockif ident strings.

[jhb]

Summary

The ident string for NVMe and VirtIO block deivces do not contain the
bus, and the various fields can potentially use up to three characters
when printed as unsigned values (full range of uint8_t) even if not
likely in practice.

[jhb]

GCC still warns about a potential overflow after this, but I think GCC's overflow checking has an off by one error.

[corvink]

usr.sbin/bhyve/pci_nvme.c

3229

Have you tried using %u? Maybe gcc warns due to the possible minus sign of signed integers?

[chuck]

LGTM but I'm also curious if @corvink suggestion of %u helps

[jhb]

Yes, %u helps, and there's actually similar bugs in ahci and virtio_blk so I'll update the review to fix all of those.

[jhb]

Use %u, add ahci and virtio-blk