block-migration: actually disable dirty tracking on cleanup

Call to set_dirty_tracking() is misplaced.

Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
diff --git a/block-migration.c b/block-migration.c
index c9d3e81..483ca7b 100644
--- a/block-migration.c
+++ b/block-migration.c
@@ -533,6 +533,8 @@
     BlkMigDevState *bmds;
     BlkMigBlock *blk;
 
+    set_dirty_tracking(0);
+
     while ((bmds = QSIMPLEQ_FIRST(&block_mig_state.bmds_list)) != NULL) {
         QSIMPLEQ_REMOVE_HEAD(&block_mig_state.bmds_list, entry);
         qemu_free(bmds->aio_bitmap);
@@ -545,8 +547,6 @@
         qemu_free(blk);
     }
 
-    set_dirty_tracking(0);
-
     monitor_printf(mon, "\n");
 }