Update test_flash_attn.py (#17102)

Signed-off-by: ShuaibinLi <lishuaibin@live.cn>

tests/kernels/attention/test_flash_attn.py

@@ -145,7 +145,7 @@ def test_flash_attn_with_paged_kv(
     v_descale = None
     if q_dtype is not None:
         # QKV are drawn from N(0, 1): no need for a fp8 scaling factor
-        maybe_quantized_query = query.to(q_dtype)
+        maybe_quantized_query = q.to(q_dtype)
         maybe_quantized_key_cache = key_cache.to(q_dtype)
         maybe_quantized_value_cache = value_cache.to(q_dtype)