Utils: Rename winQPidToPid to qPidToPid

... and make it a no-op on non-Windows. Saves #ifdefs.

Change-Id: Ie791f7b9f1a425325d0b889e73758c5f7f7e6ad2
Reviewed-by: Friedemann Kleint <Friedemann.Kleint@digia.com>