migration: expose the bitmap_sync_count to the end

expose the count that logs the times of updating the dirty bitmap to
end user.

Signed-off-by: ChenLiang <chenliang88@huawei.com>
Signed-off-by: Gonglei <arei.gonglei@huawei.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
diff --git a/migration.c b/migration.c
index ac23275..2cb768d 100644
--- a/migration.c
+++ b/migration.c
@@ -215,6 +215,7 @@
         info->ram->normal_bytes = norm_mig_bytes_transferred();
         info->ram->dirty_pages_rate = s->dirty_pages_rate;
         info->ram->mbps = s->mbps;
+        info->ram->dirty_sync_count = s->dirty_sync_count;
 
         if (blk_mig_active()) {
             info->has_disk = true;
@@ -248,6 +249,7 @@
         info->ram->normal = norm_mig_pages_transferred();
         info->ram->normal_bytes = norm_mig_bytes_transferred();
         info->ram->mbps = s->mbps;
+        info->ram->dirty_sync_count = s->dirty_sync_count;
         break;
     case MIG_STATE_ERROR:
         info->has_status = true;