Follow up to serialization validation code

src/core/SkImageFilter.cpp

Index: src/core/SkImageFilter.cpp
diff --git a/src/core/SkImageFilter.cpp b/src/core/SkImageFilter.cpp
index 89b2cc50d8784472ed501682e6993e38864be193..e7624d334509701342d8e0e50a9278209cccaabb 100644
--- a/src/core/SkImageFilter.cpp
+++ b/src/core/SkImageFilter.cpp
@@ -57,7 +57,7 @@ SkImageFilter::SkImageFilter(SkFlattenableReadBuffer& buffer)
     : fInputCount(buffer.readInt()), fInputs(new SkImageFilter*[fInputCount]) {
     for (int i = 0; i < fInputCount; i++) {
         if (buffer.readBool()) {
-            fInputs[i] = static_cast<SkImageFilter*>(buffer.readFlattenable());
+            fInputs[i] = buffer.readFlattenableT<SkImageFilter>();
         } else {
             fInputs[i] = NULL;
         }