Fixe related on #34608: MultiLayer OpenEXR (from Maya) - passes lost in Compositor Image Node

imb_exr_split_channel_name didn't set any value to layer and pass names,
leaving them uninitialized.

This is likely solves initial report, but will know for sure after testing
windows build only.

source/blender/imbuf/intern/openexr/openexr_api.cpp

@@ -886,6 +886,8 @@ static int imb_exr_split_channel_name(ExrChannel *echan, char *layname, char *pa
 	/* some multilayers have the combined buffer with names A B G R saved */
 	if (name[1] == 0) {
 		echan->chan_id = name[0];
+		layname[0] = '\0';
+		strcpy(passname, "Combined");
 		return 1;
 	}