Fix a typo in a LenChecker docstring
diff --git a/pylint/checkers/refactoring/len_checker.py b/pylint/checkers/refactoring/len_checker.py
index 6bfe2fd..6b36681 100644
--- a/pylint/checkers/refactoring/len_checker.py
+++ b/pylint/checkers/refactoring/len_checker.py
@@ -81,7 +81,7 @@
try:
instance = next(len_arg.infer())
except astroid.InferenceError:
- # Probably undefined-varible, abort check
+ # Probably undefined-variable, abort check
return
mother_classes = self.base_classes_of_node(instance)
affected_by_pep8 = any(