fix: uv_get_osenv set length only when no buf

source/libs/function/src/tudf.c

@@ -124,7 +124,10 @@ static int32_t udfSpawnUdfd(SUdfdData *pData) {
 
   char pathTaosdLdLib[512] = {0};
   size_t taosdLdLibPathLen = sizeof(pathTaosdLdLib);
-  uv_os_getenv("LD_LIBRARY_PATH", pathTaosdLdLib, &taosdLdLibPathLen);
+  int ret = uv_os_getenv("LD_LIBRARY_PATH", pathTaosdLdLib, &taosdLdLibPathLen);
+  if (ret != UV_ENOBUFS) {
+    taosdLdLibPathLen = strlen(pathTaosdLdLib);
+  }
 
   char udfdPathLdLib[1024] = {0};
   size_t udfdLdLibPathLen = strlen(tsUdfdLdLibPath);