Fix typo in GridSearchCV documentation (scikit-learn#8739)

Author: Ilya

sklearn/model_selection/_search.py

@@ -818,8 +818,8 @@ class GridSearchCV(BaseSearchCV):
     >>> from sklearn.model_selection import GridSearchCV
     >>> iris = datasets.load_iris()
     >>> parameters = {'kernel':('linear', 'rbf'), 'C':[1, 10]}
-    >>> svr = svm.SVC()
-    >>> clf = GridSearchCV(svr, parameters)
+    >>> svc = svm.SVC()
+    >>> clf = GridSearchCV(svc, parameters)
     >>> clf.fit(iris.data, iris.target)
     ...                             # doctest: +NORMALIZE_WHITESPACE +ELLIPSIS
     GridSearchCV(cv=None, error_score=...,