tcp_hostcache: limit scope of struct hc_metrics_lite and rename with tcp_ prefix

[rscheff]

Summary

For some reason, the scope of the struct hc_metrics_lite was not restricted
to kernel modules but also visible to userspace. As the naming also reflected
an idiosyncracy, prefix with tcp_ and restrict the scope to the kernel only.

[glebius]

If renaming, I would suggest drop the _lite prefix. It is lite only when you look from inside the hostcache module. For the rest of TCP it is just KPI structure. Doesn't make any sense outside. The name struct tcp_hc_metrics would be great. I should have done that in 09000cc133d8.

sys/netinet/tcp_var.h

910

The comment should be dropped. It must not speaking of program correctness -- we don't cast or copy one to other.

[rscheff]

• complete renaming from hc_metrics_lite to tcp_hc_metrics, including abbreviated variable names