Fully initialize m_sDecParam in TestInitUninit

Before dc2cbe4, the DecoderConfigParam function returned early
since DecoderSetCsp signaled a failure, which is why the uninitialized
parameters weren't read before.

This fixes valgrind warnings about conditional jumps depending on
uninitialized values.

test/decoder/DecUT_DecExt.cpp

@@ -203,6 +203,7 @@ void DecoderInterfaceTest::TestInitUninit() {
     EXPECT_EQ (eRet, cmInitExpected);
   }
   //Initialize first, can get input color format
+  Init();
   m_sDecParam.bParseOnly = false;
   m_pDec->Initialize (&m_sDecParam);