xfree86: Take second reference for SavedCursor in xf86CursorSetCursor
The same pointer is kept in CurrentCursor as well, therefore two RefCursor calls are needed. Fixes use-after-free after switching VTs. Closes: xorg/xserver#1067
The same pointer is kept in CurrentCursor as well, therefore two RefCursor calls are needed. Fixes use-after-free after switching VTs. Closes: xorg/xserver#1067