Reduce eqos if driver noisiness

[bscott_bunyatech.com.au]

Summary

Reduce very common console messages:
Receive error rdes3=30208000
Also count errors for netstat purposes

Also, differentiate between overflow errors and others. Still report the errors when the length is non-zero (overflow errors).

Test Plan

Confirm less console messages: Receive error rdes3=*
Confirm that netstat -i shows incrementing error count after a few large transfers (this is assuming these errors are always going to happen).

[mhorne]

LGTM.

Note, the eqos(4) driver has an uncertain future. It is possible that we will move to supporting this hardware with the dwc(4) driver instead; see https://reviews.freebsd.org/D59191 if interested.

Of course, this does not block this change, which I will merge right away.