direct3d11: fix the subpicture positions
direct3d11: fix the subpicture positions

there's was a mismatch between height/width and missing the offset of the
placed picture in the whole area.

Fixes WinRT issue #37

Signed-off-by: Jean-Baptiste Kempf <7b85a41a628204b76aba4326273a3ccc74bd009a@videolan.org>

xkfz007/vlc,xkfz007/vlc,xkfz007/vlc,xkfz007/vlc,xkfz007/vlc,xkfz007/vlc,xkfz007/vlc