[BugFix][Intel GPU] Use refactored API for dist_backend in V1 worker (#20596)

Signed-off-by: ratnampa <ratnam.parikh@intel.com>

vllm/v1/worker/xpu_worker.py

@@ -148,11 +148,11 @@ class XPUWorker(Worker):
         os.environ["CCL_ATL_TRANSPORT"] = ENV_CCL_ATL_TRANSPORT
         os.environ["LOCAL_WORLD_SIZE"] = ENV_LOCAL_WORLD_SIZE
         os.environ["LOCAL_RANK"] = str(self.local_rank)
-        dist_backend = "ccl"
 
         init_worker_distributed_environment(self.vllm_config, self.rank,
                                             self.distributed_init_method,
-                                            self.local_rank, dist_backend)
+                                            self.local_rank,
+                                            current_platform.dist_backend)
 
         # global all_reduce needed for overall oneccl warm up
         torch.distributed.all_reduce(torch.zeros(1).xpu())