[locator] fix doc for GetProvider::Get() implementation location (#12690)

src/core/common/locator.hpp

@@ -90,7 +90,7 @@ public:
      *
      * @returns A reference to the `Type` object of the instance.
      */
-    template <typename Type> inline Type &Get(void) const; // Implemented in `locator_getters.hpp`.
+    template <typename Type> inline Type &Get(void) const; // Implemented in `instance.hpp`.
 
 protected:
     GetProvider(void) = default;