[PATCH] conditional remove of trailing sysfs whitespace

[PATCH] conditional remove of trailing sysfs whitespace

Hey, it may never happen, that one wants to distinguish attributes by
trailing spaces, but we should not lose the control over it, just for
being lazy :)

Here we remove the trailing spaces of the sysfs attribute only if the
configured value to match doesn't have any trailing spaces by itself.
So if you put a attribute in a rule with spaces at the end, the sysfs
attribute _must_ match exactly.

Is that cool for everyone?

As usual, 2 tests are added for it with a artificial sysfs file and
a few words to the man page.