Print of incomplete type in async_op_cuda.h

[PhilMiller]

vt/lib/fmt/include/fmt/core.h(1206): error: incomplete type is not allowed
          detected during:
            instantiation of "int fmt::v7::detail::arg_mapper<Context>::map(const T *) [with Context=fmt::v7::basic_format_context<fmt::v7::detail::buffer_appender<char>, char>, T=CUevent_st]" 
(1438): here
            instantiation of "fmt::v7::detail::value<Context> fmt::v7::detail::make_arg<IS_PACKED,Context,<unnamed>,T,<unnamed>>(const T &) [with IS_PACKED=true, Context=fmt::v7::basic_format_context<fmt::v7::detail::buffer_appender<char>, char>, <unnamed>=fmt::v7::detail::type::int_type, T=CUevent_st *, <unnamed>=0]" 
(1589): here
            instantiation of "fmt::v7::format_arg_store<Context, Args...>::format_arg_store(const Args &...) [with Context=fmt::v7::basic_format_context<fmt::v7::detail::buffer_appender<char>, char>, Args=<CUevent_st *, const char *, const char *>]" 
(1626): here
            instantiation of "auto fmt::v7::make_args_checked<Args...,S,Char>(const S &, const fmt::v7::remove_reference_t<Args> &...)->fmt::v7::format_arg_store<fmt::v7::buffer_context<Char>, fmt::v7::remove_reference_t<Args>...> [with Args=<cudaEvent_t &, const char *, const char *>, S=char [37], Char=char]" 
(2075): here
            instantiation of "std::__cxx11::basic_string<Char, std::char_traits<Char>, std::allocator<Char>> fmt::v7::format(const S &, Args &&...) [with S=char [37], Args=<cudaEvent_t &, const char *, const char *>, Char=char]" 
vt/src/vt/messaging/async_op_cuda.h(92): here