port-i386/53128: Boot says "default boot twice, skipping..."

[gson%gson.org@localhost (Andreas Gustafsson)]

>Number:         53128
>Category:       port-i386
>Synopsis:       Boot says "default boot twice, skipping..."
>Confidential:   no
>Severity:       non-critical
>Priority:       medium
>Responsible:    port-i386-maintainer
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Sun Mar 25 10:15:00 +0000 2018
>Originator:     Andreas Gustafsson
>Release:        NetBSD-current, source date >= 2018.03.02.00.25.26
>Organization:

>Environment:

System: NetBSD
Architecture: i386
Machine: i386
>Description:

Since the commit of src/etc/etc.i386/boot.cfg 1.5, the i386 testbed
on babylon5.netbsd.org has logged the message "default boot twice, skipping..."
on every boot.

Here's one log file containing the message:

  http://releng.netbsd.org/b5reports/i386/2018/2018.03.02.06.41.18/test.log

>How-To-Repeat:

Inspect the test logs.

>Fix: