style: small refactor in struct_impl.py

Author: MrIndeciso

libdestruct/common/struct/struct_impl.py

@@ -74,13 +74,12 @@ def compute_own_size(cls: type[struct_impl], reference_type: type) -> None:
                 # Field associated with the annotation
                 field = getattr(reference_type, name)
                 attribute = cls._inflater.inflater_for((field, annotation))(None)
-                size += attribute.size
             elif isinstance(annotation, Field):
                 attribute = cls._inflater.inflater_for((annotation, annotation.base_type))(None)
-                size += attribute.size
             else:
                 attribute = cls._inflater.inflater_for(annotation)
-                size += attribute.size
+
+            size += attribute.size
 
         cls.size = size