QMediaPlayer::setPosition: position set doens't match the argument

When calling setPosition the position set is now always accurate. In the attached sample project the position is set to somewhere close to 4000 (ususually 4010 or similar) when there's an attempt to set it to 4000. Spamming setPosition may eventually get it right.

Also this does not occur with all files. So far managed to reproduce this only with mp3 audio files. In the meanwhile there was no problem with a mp4 video.

Steps to reproduce the problem:

• Build the attached sample and run
• Select an mp3 audio file
• Play
• Pause
• press "set position to 4000" and observe the result.