Bug 1401706: Remove redundant UpdateValueDisplay call. r=Ehsan

This was just moved from the old code, but we always call that function in
CreateAnonymousContent, so no need to.

MozReview-Commit-ID: 1zqmQM2KdpW
Signed-off-by: Emilio Cobos Álvarez <emilio@crisal.io>

layout/forms/nsTextControlFrame.cpp

@@ -483,7 +483,7 @@ nsTextControlFrame::CreateRootNode()
                                    classValue, false);
   NS_ENSURE_SUCCESS(rv, rv);
 
-  return UpdateValueDisplay(false);
+  return NS_OK;
 }
 
 void