Ease down InferPrint debug printing

Summary:
InferPrint sets developer_mode by default, so tighten check for debug
printing.

Reviewed By: jvillard

Differential Revision: D3287792

fbshipit-source-id: 2a01c7b

infer/src/backend/config.ml

@@ -919,7 +919,7 @@ let post_parsing_initialization () =
 
 let parse_args_and_return_usage_exit =
   let usage_exit = CLOpt.parse "INFER_ARGS" exe_usage in
-  if !debug || !developer_mode then
+  if !debug || (!developer_mode && not (CLOpt.current_exe = CLOpt.P)) then
     prerr_endline
       ((Filename.basename Sys.executable_name) ^ " got args "
        ^ (try Unix.getenv "INFER_ARGS" with Not_found -> "")) ;