Linter.py: Fix GlobalBear example in docstring
Linter.py: Fix GlobalBear example in docstring

Replaces filename as it doesn't exist
in this scope. And uses file_dict to have
access to all the files.

Closes #4939

Nosferatul/coala,jayvdb/coala,coala/coala,Nosferatul/coala,SanketDG/coala,coala-analyzer/coala,SanketDG/coala,coala/coala,karansingh1559/coala,coala-analyzer/coala,jayvdb/coala,coala-analyzer/coala,Nosferatul/coala,SanketDG/coala,jayvdb/coala,karansingh1559/coala,karansingh1559/coala,coala/coala