bin/51175: swapctl -A should honor already activated swap devices

[netbsd@benjaminlorenz.email]

	Note: There was a bad value `' for the field `Confidential'.
	It was set to the default value of `yes'.

>Number:         51175
>Category:       bin
>Synopsis:       swapctl -A should honor already activated swap devices
>Confidential:   yes
>Severity:       non-critical
>Priority:       low
>Responsible:    bin-bug-people
>State:          open
>Class:          change-request
>Submitter-Id:   net
>Arrival-Date:   Sat May 28 16:25:00 +0000 2016
>Originator:     Benjamin Lorenz
>Release:        NetBSD 7.99.29
>Organization:
	
>Environment:
	
	
System: NetBSD db.qwabbl.com 7.99.29 NetBSD 7.99.29 (GENERIC) #0: Sat May 28 13:42:23 CEST 2016 root%db.qwabbl.com@localhost:/usr/obj/sys/arch/amd64/compile/GENERIC amd64
Architecture: x86_64
Machine: amd64
>Description:
swapctl -A and swapon -a should behave similar to mount -a such that
already activated swap devices from /etc/fstab are not tried to be activated
again, thus producing an error message.
	
>How-To-Repeat:
	
>Fix:
	

>Unformatted: