fix whitespace errors

testing/examples/ob-C-test.org

@@ -8,7 +8,7 @@
 #+begin_src cpp :includes "<iostream>" :results silent
   std::cout << 42;
   return 0;
-#+end_src 
+#+end_src
 
 #+source: integer_var
 #+begin_src cpp :var q=12 :includes "<iostream>" :results silent