Fix #140942: FBX importer fails when using file browser recursive option

The `files` property, provided by the blender file browser, contain
paths relative to the `directory` property. Use that instead of using
the file's parent directory.

Pull Request: https://projects.blender.org/blender/blender/pulls/141575

scripts/addons_core/io_scene_fbx/__init__.py

@@ -215,9 +215,8 @@ class ImportFBX(bpy.types.Operator, ImportHelper):
 
         if self.files:
             ret = {'CANCELLED'}
-            dirname = os.path.dirname(self.filepath)
             for file in self.files:
-                path = os.path.join(dirname, file.name)
+                path = os.path.join(self.directory, file.name)
                 if import_fbx.load(self, context, filepath=path, **keywords) == {'FINISHED'}:
                     ret = {'FINISHED'}
             return ret