[buck-clang] don't force number of buck threads

Summary: Buck uses its own estimate for how many workers to spawn, there is no need to pass our own estimate for capture.

Reviewed By: ezgicicek

Differential Revision: D22065565

fbshipit-source-id: 4c062a9aa

infer/src/integration/BuckFlavors.ml

@@ -24,8 +24,7 @@ let add_flavors_to_buck_arguments buck_mode ~extra_flavors original_buck_args =
 
 
 let capture_buck_args () =
-  ["--show-output"; "-j"; Int.to_string Config.jobs]
+  ("--show-output" :: (if Config.keep_going then ["--keep-going"] else []))
-  @ (if Config.keep_going then ["--keep-going"] else [])
   @ (match Config.load_average with Some l -> ["-L"; Float.to_string l] | None -> [])
   @ Buck.config ClangFlavors @ List.rev Config.buck_build_args