Drop race warning about config.running

tools/valgrind/starpu.suppr

@@ -0,0 +1,13 @@
+{
+   config.running is not racy from starpu_shutdown
+   Helgrind:Race
+   fun:starpu_shutdown
+   fun:main
+}
+
+{
+   config.running is not racy from _starpu_machine_is_running
+   Helgrind:Race
+   fun:_starpu_machine_is_running
+   ...
+}