unittest-seastar-socket: debug to error on unexpected return from dispatch_rw_bounded

Related: https://tracker.ceph.com/issues/64457
Signed-off-by: Samuel Just <[email protected]>

Author: athanatos

src/test/crimson/test_socket.cc

@@ -449,7 +449,7 @@ future<> test_unexpected_down(bool is_fixed_cpu) {
     [](auto cs) {
       return Connection::dispatch_rw_bounded(cs, 128, true
         ).handle_exception_type([](const std::system_error& e) {
-        logger().debug("test_unexpected_down(): client get error {}", e);
+        logger().error("test_unexpected_down(): client get error {}", e);
         ceph_assert(e.code() == error::read_eof);
       });
     },