module: avoid passing unnecessary loop reference

It's a sync request, which doesn't require the loop parameter to be set.

PR-URL: #29275
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Richard Lau <riclau@uk.ibm.com>
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: James M Snell <jasnell@gmail.com>

Author: saghul

src/module_wrap.cc

@@ -462,7 +462,7 @@ std::string ReadFile(uv_file file) {
   uv_buf_t buf = uv_buf_init(buffer_memory, sizeof(buffer_memory));
 
   do {
-    const int r = uv_fs_read(uv_default_loop(),
+    const int r = uv_fs_read(nullptr,
                              &req,
                              file,
                              &buf,