Fix 'Eq2 HashMap' instance

Author: rockbmb

Data/HashMap/Base.hs

@@ -254,7 +254,7 @@ instance Traversable (HashMap k) where
     traverse f = traverseWithKey (const f)
 
 #if MIN_VERSION_base(4,9,0)
-instance Eq2 HashMapInner where
+instance Eq2 HashMap where
     liftEq2 = equal
 
 instance Eq k => Eq1 (HashMap k) where