bin/50126: ndp(8) does nothing with -f option

[ozaki-r%netbsd.org@localhost]

>Number:         50126
>Category:       bin
>Synopsis:       ndp(8) does nothing with -f option
>Confidential:   no
>Severity:       non-critical
>Priority:       low
>Responsible:    bin-bug-people
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Wed Aug 05 08:10:01 +0000 2015
>Originator:     Ryota Ozaki
>Release:        current
>Organization:
>Environment:
NetBSD rangeley 7.99.20 NetBSD 7.99.20 (RANGELEY) #10: Tue Jul 28 09:45:16 JST 2015  ozaki-r@(hidden) amd64
>Description:
ndp(8) has -f option which reads pairs of an IP address and a MAC address from a file
and applies them to the kernel. However, it doesn't work (not implemented).

We should implement the feature or remove it from ndp.8 and the help message.
>How-To-Repeat:
# cat > list <<EOF
fc00::1 b2:a0:53:5b:96:01
fc00::2 b2:a0:53:5b:96:02
EOF
# ndp -f list
# ndp -a -n

>Fix:
N/A