migration: Use always helper to set state

There were three places that were not using the migrate_set_state()
helper, just fix that.

Signed-off-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
diff --git a/migration/migration.c b/migration/migration.c
index 5c1233f..78eb715 100644
--- a/migration/migration.c
+++ b/migration/migration.c
@@ -549,7 +549,7 @@
 {
     trace_migrate_fd_error();
     assert(s->file == NULL);
-    s->state = MIGRATION_STATUS_FAILED;
+    migrate_set_state(s, MIGRATION_STATUS_SETUP, MIGRATION_STATUS_FAILED);
     trace_migrate_set_state(MIGRATION_STATUS_FAILED);
     notifier_list_notify(&migration_state_notifiers, s);
 }
@@ -634,7 +634,7 @@
     s->parameters[MIGRATION_PARAMETER_DECOMPRESS_THREADS] =
                decompress_thread_count;
     s->bandwidth_limit = bandwidth_limit;
-    s->state = MIGRATION_STATUS_SETUP;
+    migrate_set_state(s, MIGRATION_STATUS_NONE, MIGRATION_STATUS_SETUP);
     trace_migrate_set_state(MIGRATION_STATUS_SETUP);
 
     s->total_time = qemu_clock_get_ms(QEMU_CLOCK_REALTIME);
@@ -733,7 +733,7 @@
     } else {
         error_setg(errp, QERR_INVALID_PARAMETER_VALUE, "uri",
                    "a valid migration protocol");
-        s->state = MIGRATION_STATUS_FAILED;
+        migrate_set_state(s, MIGRATION_STATUS_SETUP, MIGRATION_STATUS_FAILED);
         return;
     }