Do the early return when role is different than UnknownRole

Source/modules/accessibility/AXRenderObject.cpp

Index: Source/modules/accessibility/AXRenderObject.cpp
diff --git a/Source/modules/accessibility/AXRenderObject.cpp b/Source/modules/accessibility/AXRenderObject.cpp
index aaccaacbfc23aac6aa405be6ee28755266f7de4e..2c9a3b9191db5d62d1dd4cedd5005226fd4ff188 100644
--- a/Source/modules/accessibility/AXRenderObject.cpp
+++ b/Source/modules/accessibility/AXRenderObject.cpp
@@ -258,13 +258,10 @@ AccessibilityRole AXRenderObject::determineAccessibilityRole()
     if (!m_renderer)
         return UnknownRole;
 
-    m_ariaRole = determineAriaRoleAttribute();
+    if ((m_ariaRole = determineAriaRoleAttribute()) != UnknownRole)
+        return m_ariaRole;
 
     Node* node = m_renderer->node();
-    AccessibilityRole ariaRole = ariaRoleAttribute();
-    if (ariaRole != UnknownRole)
-        return ariaRole;
-
     RenderBoxModelObject* cssBox = renderBoxModelObject();
 
     if (node && node->isLink()) {