fix some wrong words in comment

src/Interpreters/ActionsDAG.h

@@ -80,7 +80,7 @@ public:
     };
 
     /// Index is used to:
-    ///     * find Node buy it's result_name
+    ///     * find Node by it's result_name
     ///     * specify order of columns in result
     /// It represents a set of available columns.
     /// Removing of column from index is equivalent to removing of column from final result.

src/Interpreters/ExpressionActions.h

@@ -62,7 +62,7 @@ public:
 
     using Actions = std::vector<Action>;
 
-    /// This map helps to find input position bu it's name.
+    /// This map helps to find input position by it's name.
     /// Key is a view to input::result_name.
     /// Result is a list because it is allowed for inputs to have same names.
     using NameToInputMap = std::unordered_map<std::string_view, std::list<size_t>>;