[Utils] Fix indentation error in utils/wciia.py

Running this script gives
```
"llvm-project/llvm/./utils/wciia.py", line 56
    if word == "N:":
TabError: inconsistent use of tabs and spaces in indentation
```
Under emacs' whitespace-mode, it shows
```
for·line·in·code_owners_file:$
····for·word·in·line.split():$
»       if·word·==·"N:":$
»       »       name·=·line[2:].strip()$
»       »       if·code_owner:$
»       »       »       process_code_owner(code_owner)$
»       »       »       code_owner·=·{}$
```
I use `yapf` to format this script directly and it's running correctly.