[NVIDIA] Fix use case of SGLANG_ENABLE_FLASHINFER_GEMM (#13274)

Co-authored-by: Baizhou Zhang <sobereddiezhang@gmail.com>

python/sglang/srt/environ.py

@@ -206,7 +206,7 @@ class Envs:
 
     # Flashinfer
     SGLANG_IS_FLASHINFER_AVAILABLE = EnvBool(True)
-    SGLANG_ENABLE_FLASHINFER_GEMM = EnvBool(False)
+    SGLANG_ENABLE_FLASHINFER_FP8_GEMM = EnvBool(False)
     # Default to the pick from flashinfer
     SGLANG_FLASHINFER_FP4_GEMM_BACKEND = EnvStr("")
     SGLANG_FLASHINFER_WORKSPACE_SIZE = EnvInt(384 * 1024 * 1024)
@@ -307,6 +307,9 @@ def _print_deprecated_env(new_name: str, old_name: str):
 
 def _convert_SGL_to_SGLANG():
     _print_deprecated_env("SGLANG_LOG_GC", "SGLANG_GC_LOG")
+    _print_deprecated_env(
+        "SGLANG_ENABLE_FLASHINFER_FP8_GEMM", "SGLANG_ENABLE_FLASHINFER_GEMM"
+    )
 
     for key, value in os.environ.items():
         if key.startswith("SGL_"):