This allows us to free said view in the case of a syntax error. This
also allows us to get rid of a few places where we tried to clean up
the view ourselves in the parsing code.

Found by Valgrind.

Currently callers of this function are responsible for setting the draw buffer
correctly, but they don't do a very good job:
  - swapchain_init() sets the draw buffer to GL_BACK if there's a back buffer,
    even though the context's target is always the front buffer.
  - swapchain_create_context_for_thread() depends on (eventually) being called
    by FindContext().
  - create_primary_opengl_context() and
    IWineD3DSwapChainImpl_SetDestWindowOverride() don't bother setting a draw
    buffer at all.
Just marking the draw buffer dirty lets the context management sort it all
out, and is much simpler.

Casting the container to "IWineD3DSwapChainImpl *" is always safe when
SFLAG_SWAPCHAIN is set on the surface. Most callers don't have a real
need for the swapchain, and end up calling GetContainer() just to pass
it to surface_get_gl_buffer().

Found by Valgrind.

Found by Valgrind.

Found by Valgrind.

Found by Valgrind.

Found by Valgrind.