bin/53107: gpt(8) with no device argument problems

[msaitoh%execsw.org@localhost]

>Number:         53107
>Category:       bin
>Synopsis:       gpt(8) with no device argument problems
>Confidential:   no
>Severity:       non-critical
>Priority:       low
>Responsible:    bin-bug-people
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Mon Mar 19 06:25:00 +0000 2018
>Originator:     msaitoh%execsw.org@localhost
>Release:        NetBSD 8.99.12
>Organization:
>Environment:
netbsd-8 or -current
Architecture: x86_64
Machine: amd64
>Description:
	On netbsd-8 or -current:

	    gpt show -a
	    Segmentation fault (core dumped)

	Other than "set -l" and "type -l" take device argument.
	If no device argument with such command, it dumps core.

	gpt(8)'s SYNOPSIS says:

	    SYNOPSIS
	    gpt [-nrqv] [-m mediasize] [-s sectorsize] [-T timestamp] command
	    [command_options] device

	It's incorrect for "set -l" and "type -l"

>How-To-Repeat:
	See above.
>Fix:
	Fix both code and the manual.