Bug 745287 - Fix recent a11y build warnings; r=davidb,capella

accessible/src/generic/FormControlAccessible.cpp

@@ -119,13 +119,13 @@ ProgressMeterAccessible<Max>::Value(nsString& aValue)
 
   double maxValue = 0;
   nsresult rv = GetMaximumValue(&maxValue);
-  NS_ENSURE_SUCCESS(rv, );
-  if (maxValue == 0)
+  if (NS_FAILED(rv) || maxValue == 0)
     return;
 
   double curValue = 0;
   GetCurrentValue(&curValue);
-  NS_ENSURE_SUCCESS(rv, );
+  if (NS_FAILED(rv))
+    return;
 
   // Treat the current value bigger than maximum as 100%.
   double percentValue = (curValue < maxValue) ?

accessible/src/html/nsHTMLImageAccessible.cpp

@@ -243,8 +243,7 @@ nsHTMLImageAccessible::GetLongDescURI() const
   nsDocAccessible* document = Document();
   if (document) {
     IDRefsIterator iter(document, mContent, nsGkAtoms::aria_describedby);
-    nsIContent* target = nsnull;
-    while (target = iter.NextElem()) {
+    while (nsIContent* target = iter.NextElem()) {
       if ((target->IsHTML(nsGkAtoms::a) || target->IsHTML(nsGkAtoms::area)) &&
           target->HasAttr(kNameSpaceID_None, nsGkAtoms::href)) {
         nsGenericHTMLElement* element =