COPYING: drop double-space the Copyright example

COPYING: drop double-space the Copyright example

I am assuming that the COPYING boilerplate is the source for all the
varying double-space instances we have (had) in-tree.

Update those, so we can avoid them in the future.

As always, the typical IANAL disclaimer applies. To the best of my
knowledge and understanding the two forms are identical. With the
original being _slightly_ annoying especially if your editor
high-lights the double-space.

Signed-off-by: Emil Velikov <emil.l.velikov@gmail.com>
Link: https://github.com/kmod-project/kmod/pull/450
Signed-off-by: Lucas De Marchi <ldemarchi@kernel.org>