stream: fix sectors not allocated test

The test on sectors not allocated can fail if the L1/L2 tables are
not on disk yet.  Allow tests to shutdown the VM early.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
diff --git a/tests/qemu-iotests/030 b/tests/qemu-iotests/030
index 38abc2c..0d2f87b 100755
--- a/tests/qemu-iotests/030
+++ b/tests/qemu-iotests/030
@@ -78,6 +78,7 @@
                     completed = True
 
         self.assert_no_active_streams()
+        self.vm.shutdown()
 
         self.assertFalse('sectors not allocated' in qemu_io('-c', 'map', test_img),
                          'image file not fully populated after streaming')