The change made in e835ee68e1 did not
follow the convention for relative path symlinks. Per the convention,
paths be prefixed with `${BINDIR}`, not `/bin/`. `${BINDIR}` can be
modified from the Makefile, on the command line, or in the
environment. This convention is the canonically correct way to do
things.
This follows the convention used in `bin/pkill/Makefile`,
`bin/timeout/Makefile`, etc.
MFC after: 1 week
MFC with: f05948d4e9
MFC with: e835ee68e1
Requested by: jrtc27, kevans
22dc8901a7