elements/gstqtvideosink/autotest.cpp update 3 test functions to deal with getting a sample
elements/gstqtvideosink/autotest.cpp update 3 test functions to deal with getting a sample

Updated genericSurfacePainterFormatsTest, glSurfacePainterFormatsTest, qtVideoSinkTest
the updates were fairly similar:
  get the sample from generateTestSample.
  get the Buffer from the sample.
  make sure the Buffer was retrieved.
  Map the memory containing the data
  access the data
  unmap the memory.

Since it was roughly the same change I just committed them together

dejunk/gstreamer,detrout/qt-gstreamer,detrout/qt-gstreamer,nasserGanjali/QtGStreamer,tswindell/qt-gstreamer,detrout/qt-gstreamer,freedesktop-unofficial-mirror/gstreamer__qt-gstreamer,knuesel/qt-gstreamer,iperry/qt-gstreamer,tswindell/qt-gstreamer,nasserGanjali/QtGStreamer,GStreamer/qt-gstreamer,knuesel/qt-gstreamer,nasserGanjali/QtGStreamer,tswindell/qt-gstreamer,dejunk/gstreamer,dejunk/gstreamer,freedesktop-unofficial-mirror/gstreamer__qt-gstreamer,iperry/qt-gstreamer,freedesktop-unofficial-mirror/gstreamer__qt-gstreamer,knuesel/qt-gstreamer,GStreamer/qt-gstreamer,GStreamer/qt-gstreamer,iperry/qt-gstreamer