The image information for multilayer openexr files are only shown on the
first draw. In the second draw the render result property is filled of
the image, making blender think the image is a render result and it want
to display information about the renderpasses. Which are not present.
It could be that in the first draw the image data is not requested as
the buttons are drawn, before the main area
This change will display both information. We should investigate how to
actually detect if this is a render result or not as similar code is
present in the `node_shader_buts_tex_environment_ex`.
Reviewed By: brecht
Maniphest Tasks: T65345
Differential Revision: https://developer.blender.org/D4987
19691e3ae2