replaced int32_t size by ssize_t (type trait trick)

datapool/PIDReader.h

@@ -136,7 +136,7 @@ public:
 		return SerializeAdapter<T>::getSerializedSize(&value);
 	}
 
-	virtual ReturnValue_t deSerialize(const uint8_t** buffer, int32_t* size,
+	virtual ReturnValue_t deSerialize(const uint8_t** buffer, ssize_t* size,
 	bool bigEndian) {
 		return SerializeAdapter<T>::deSerialize(&value, buffer, size, bigEndian);
 	}