UMG property binding fixup for real numbers doesn't always work

For UMG delegates, we currently have a fixup pass that ensures that bound functions match the signature of the native delegate. However, the fixup appears to use the wrong function name, which causes it to fail applying any signature fixup, which leads to a BP compilation error.

1. In UE4, create a new Widget BP in the editor.
2. Add a progress bar in the Designer view.
3. Create a function binding for Percent. Have it return a default value (eg: 0.5).
4. Compile and save.
5. In the graph view, rename the function binding.
6. Save and exit the editor.
7. Relaunch the project in UE5.
8. Note the compilation error.