Don't mix up printf and formatter.

Fixes #481

Author: cristianoc

analysis/reanalyze/src/EmitJson.ml

@@ -1,6 +1,6 @@
 let items = ref 0
-let start () = Format.fprintf Format.std_formatter "["
-let finish () = Format.fprintf Format.std_formatter "\n]@."
+let start () = Printf.printf "["
+let finish ()= Printf.printf "\n]\n"
 let emitClose () = "\n}"
 
 let emitItem ~ppf ~name ~kind ~file ~range ~message =