src: more idiomatic error pattern in node_wasi

Signed-off-by: James M Snell <jasnell@gmail.com>

PR-URL: nodejs#35493
Reviewed-By: Daijiro Wachi <daijiro.wachi@gmail.com>
Reviewed-By: Tobias Nießen <tniessen@tnie.de>
Reviewed-By: David Carlier <devnexen@gmail.com>
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: Rich Trott <rtrott@gmail.com>

src/node_wasi.cc

@@ -104,9 +104,9 @@ static MaybeLocal<Value> WASIException(Local<Context> context,
   js_msg =
       String::Concat(isolate, js_msg, FIXED_ONE_BYTE_STRING(isolate, ", "));
   js_msg = String::Concat(isolate, js_msg, js_syscall);
-  Local<Object> e =
-    Exception::Error(js_msg)->ToObject(context)
-      .ToLocalChecked();
+  Local<Object> e;
+  if (!Exception::Error(js_msg)->ToObject(context).ToLocal(&e))
+    return MaybeLocal<Value>();
 
   if (e->Set(context,
              env->errno_string(),
@@ -128,13 +128,11 @@ WASI::WASI(Environment* env,
   options->allocator = &alloc_info_;
   int err = uvwasi_init(&uvw_, options);
   if (err != UVWASI_ESUCCESS) {
-    Local<Context> context = env->context();
-    MaybeLocal<Value> exception = WASIException(context, err, "uvwasi_init");
-
-    if (exception.IsEmpty())
+    Local<Value> exception;
+    if (!WASIException(env->context(), err, "uvwasi_init").ToLocal(&exception))
       return;
 
-    context->GetIsolate()->ThrowException(exception.ToLocalChecked());
+    env->isolate()->ThrowException(exception);
   }
 }