Add trailing newlines to siphash examples.

I'm not sure if I'll actually release this example. I don't think it does a
good job of demonstrating what I wanted.

[SVN r84249]

examples/siphash/siphash.cpp

@@ -88,4 +88,4 @@ namespace hash
 
         return v0 ^ v1 ^ v2 ^ v3;
     }
-}
+}