update Deepseek-R1 tutorial.

Signed-off-by: Gongdayao <gongdayao@foxmail.com>

Author: Gongdayao

docs/source/tutorials/DeepSeek-R1.md

@@ -289,4 +289,4 @@ export VLLM_USE_MODELSCOPE=true
 vllm bench serve --model path/DeepSeek-R1-w8a8  --dataset-name random --random-input 200 --num-prompt 200 --request-rate 1 --save-result --result-dir ./
 ```
 
-After about several minutes, you can get the performance evaluation result.
+After about several minutes, you can get the performance evaluation result.