[NFC][SYCL] Replace weak_ptr::lock() with expired() when ptr copy is not needed (#13365)

Signed-off-by: Tikhomirova, Kseniya <[email protected]>

Author: KseniyaTikhomirova

sycl/source/detail/event_impl.cpp

@@ -248,7 +248,7 @@ void event_impl::wait(std::shared_ptr<sycl::detail::event_impl> Self,
     throw sycl::exception(make_error_code(errc::invalid),
                           "wait method cannot be used for a discarded event.");
 
-  if (MGraph.lock()) {
+  if (!MGraph.expired()) {
     throw sycl::exception(make_error_code(errc::invalid),
                           "wait method cannot be used for an event associated "
                           "with a command graph.");