Fix #1516: Remove unnecessary injectBackReference method

Author: JacksonJang

src/main/java/tools/jackson/databind/deser/bean/BeanDeserializer.java

@@ -682,7 +682,7 @@ protected Object _deserializeUsingPropertyBased(final JsonParser p, final Deseri
             if (prop instanceof ManagedReferenceProperty managedProp) {
                 Object value = buffer.getParameter(ctxt, prop);
                 if (value != null) {
-                    managedProp.injectBackReference(ctxt, bean, value);
+                    managedProp.set(ctxt, bean, value);
                 }
             }
         }

src/main/java/tools/jackson/databind/deser/impl/ManagedReferenceProperty.java

@@ -81,17 +81,6 @@ public Object setAndReturn(DeserializationContext ctxt, Object instance, Object
         return delegate.setAndReturn(ctxt, instance, value);
 	}
 
-    /**
-     * Inject back reference into value without setting forward reference.
-     * Used for creator properties where forward reference is already set via constructor.
-     *
-     * @since 3.0
-     */
-    public void injectBackReference(DeserializationContext ctxt, Object bean, Object value)
-    {
-        _setBackReference(ctxt, bean, value);
-    }
-
     /*
     /**********************************************************************
     /* Helper classes