Don't deserialise an array that's NULL

* This should only happen if serialisation corruption is detected, but in that
  case we don't want to crash.

renderdoc/serialise/serialiser.h

@@ -1921,7 +1921,7 @@ struct ScopedDeserialiseArray
   }
   ~ScopedDeserialiseArray()
   {
-    if(m_Ser.IsReading())
+    if(m_Ser.IsReading() && *m_El)
     {
       for(uint64_t i = 0; i < count; i++)
         Deserialise((*m_El)[i]);