net: Hyper-V: Deletion of an unnecessary check before the function call "vfree"

[SF Markus Elfring]

> Whereas if you learn how to base your changes cleanly on the correct
> base now, all of your future submissions will go quickly and smoothly
> into my tree.

My reluctance to work with more Linux repositories will evolve
over time. The faster affected software versions can be rebuilt
the more it will become interesting to try even more source
code improvements out, won't it?

I find it nice that you could accept update suggestions for
a few other Linux components already.

Regards,
Markus