Bug#865528: don't escape dash (\x2d) when logging

[積丹尼 Dan Jacobson]

By the way, the user might think he got it wright when there is plenty
of output,
$ systemctl show 'XXXXXdev-disk-by\x2dpartuuid-000ed2c3\x2d05.device'|wc
     34      35     848

But in fact he can get even more...
$ systemctl show 'dev-disk-by\x2dpartuuid-000ed2c3\x2d05.device'|wc
     40      51    1219

MB> That's a separate issue. I'm not entirely sure why
MB> systemctl status does-not-exist.service
MB> and
MB> systemctl status does-not-exist.device
MB> differ regarding their behaviour. You'd probably need to ask upstream
MB> about that.

Maybe you could report that for me. I don't know about any of that.

Anyway I don't understand what all the escaping dash is about.

If it is like shell options, then only require escaping it after a
space.

If it is a math operator, then require $(( )) like shell or something.

Else it is just like having to write %2D in URLs, when in the end it
shouldn't matter.