Minor syntax fix: #endif ... -> #endif //...

Author: xparq

src/VERSION

@@ -1 +1 @@
-0.17.5
+0.17.6

src/math/sign.hh

@@ -13,4 +13,4 @@ T sign(T x) {
 }
 
 }; // namespace
-#endif _SZ_SIGN_HH_
+#endif // _SZ_SIGN_HH_