Trace event CP begin when the first CP starpu data is effectively sent

mpi/src/mpi_failure_tolerance/starpu_mpi_checkpoint_tracker.c

@@ -58,6 +58,7 @@ static inline void _starpu_mpi_checkpoint_domain_tracker_entry_init(struct _star
 	entry->tracker.cp_domain = -1;
 	entry->tracker.cp_template = NULL;
 	entry->tracker.ack_msg_count = 0;
+	entry->tracker.first_msg_sent_flag = 0;
 	entry->tracker.valid = 0;
 	entry->tracker.old = 0;
 }

mpi/src/mpi_failure_tolerance/starpu_mpi_checkpoint_tracker.h

@@ -32,6 +32,7 @@ struct _starpu_mpi_checkpoint_tracker
 	int                              cp_domain;
 	starpu_mpi_checkpoint_template_t cp_template;
 	int                              ack_msg_count;
+	int                              first_msg_sent_flag;
 	int                              old:1;
 	int                              valid: 1;
 };