build fix follow up on status_t/ssize_t changes.

* added a TODO in packagefs.

headers/private/package/hpkg/DataWriters.h

@@ -71,7 +71,7 @@ public:
 
 private:
 	// BDataOutput
-	virtual	status_t			Write(const void* buffer, size_t size);
+	virtual	ssize_t				Write(const void* buffer, size_t size);
 
 private:
 			AbstractDataWriter*	fDataWriter;