[Misc] Fix Unable to detect current VLLM config. Defaulting to NHD kv cache layout warning (#20400)

Signed-off-by: NickLucche <nlucches@redhat.com>

vllm/v1/attention/backends/utils.py

@@ -138,7 +138,7 @@ def get_kv_cache_layout():
     if cache_layout is None:
         cache_layout = get_kv_connector_cache_layout()
     else:
-        logger.info_once("`FLASHINFER_KV_CACHE_LAYOUT` environment variable " \
+        logger.info_once("`VLLM_KV_CACHE_LAYOUT` environment variable " \
         "detected. Setting KV cache layout to %s.", cache_layout)
 
     return cache_layout