include/starpu_sched_ctx.h: add C++ guard

include/starpu_sched_ctx.h

@@ -19,6 +19,11 @@
 
 #include <starpu.h>
 
+#ifdef __cplusplus
+extern "C"
+{
+#endif
+
 /* generic structure used by the scheduling contexts to iterate the workers */
 struct starpu_sched_ctx_worker_collection
 {
@@ -127,4 +132,8 @@ void starpu_sched_ctx_set_inheritor(unsigned sched_ctx, unsigned inheritor);
 
 void starpu_sched_ctx_finished_submit(unsigned sched_ctx_id);
 
+#ifdef __cplusplus
+}
+#endif
+
 #endif /* __STARPU_SCHED_CTX_H__ */