`bound_form.cleaned_data` already returns the file data if there was any.

`bound_form.files` returns a `MultiValueDict` which errors when passing
`.CONTENT` into a model constructor.

djangorestframework/resources.py

@@ -241,14 +241,12 @@ class FormResource(Resource):
         # In addition to regular validation we also ensure no additional fields are being passed in...
         unknown_fields = seen_fields_set - (form_fields_set | allowed_extra_fields_set)
         unknown_fields = unknown_fields - set(('csrfmiddlewaretoken', '_accept', '_method'))  # TODO: Ugh.
-
+        
         # Check using both regular validation, and our stricter no additional fields rule
         if bound_form.is_valid() and not unknown_fields:
             # Validation succeeded...
             cleaned_data = bound_form.cleaned_data
 
-            cleaned_data.update(bound_form.files)
-
             # Add in any extra fields to the cleaned content...
             for key in (allowed_extra_fields_set & seen_fields_set) - set(cleaned_data.keys()):
                 cleaned_data[key] = data[key]