librbd: avoid aggregate-initializing any static_visitor

This will result in an error complaining about a protected dtor.
also see:
    https://github.com/ceph/ceph/pull/26838

Signed-off-by: Willem Jan Withagen <wjw@digiware.nl>
(cherry picked from commit 8abfb42856bfdef1318ba4a178555d95aeeaaf8b)

diff --git a/src/test/librbd/operation/test_mock_TrimRequest.cc b/src/test/librbd/operation/test_mock_TrimRequest.cc
index 15e9bdd055e29583b39816498e1e8ea526e8bab5..39b54f9708bfd49179fd100d3d939f3a42f41cc9 100644 (file)
--- a/src/test/librbd/operation/test_mock_TrimRequest.cc
+++ b/src/test/librbd/operation/test_mock_TrimRequest.cc
@@ -183,7 +183,7 @@ public:
     EXPECT_CALL(*mock_image_ctx.io_object_dispatcher, send(_))
       .WillOnce(Invoke([&mock_image_ctx, offset, length, update_object_map, r]
                        (io::ObjectDispatchSpec* spec) {
-                  auto discard = boost::apply_visitor(io::DiscardVisitor{}, spec->request);
+                  auto discard = boost::apply_visitor(io::DiscardVisitor(), spec->request);
                   ASSERT_TRUE(discard != nullptr);
                   ASSERT_EQ(offset, discard->object_off);
                   ASSERT_EQ(length, discard->object_len);