fix backend

Signed-off-by: jiqing-feng <jiqing.feng@intel.com>

Author: jiqing-feng

tests/fsdp_state_dict_save.py

@@ -23,7 +23,7 @@
 def _get_device_and_backend():
     """Auto-detect accelerator device and distributed backend."""
     device_type = str(torch.accelerator.current_accelerator())
-    backend_map = {"cuda": "nccl", "xpu": "ccl"}
+    backend_map = {"cuda": "nccl", "xpu": "xccl"}
     backend = backend_map.get(device_type, "gloo")
     return device_type, backend