Update Fuchsia-specific code to use the new MX_ error names

runtime/vm/os_thread_fuchsia.cc

 // Copyright (c) 2016, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include "platform/globals.h"  // NOLINT
 #if defined(HOST_OS_FUCHSIA)
 
 #include "vm/os.h"
 #include "vm/os_thread.h"
 #include "vm/os_thread_fuchsia.h"
@@ skipping 147 matching lines @@
   return kStackSize;
 }
 
 
 ThreadId OSThread::GetCurrentThreadId() {
   mx_info_handle_basic_t info;
   mx_handle_t thread_handle = thrd_get_mx_handle(thrd_current());
   mx_status_t status =
       mx_object_get_info(thread_handle, MX_INFO_HANDLE_BASIC, &info,
                          sizeof(info), nullptr, nullptr);
-  if (status != NO_ERROR) {
+  if (status != MX_OK) {
     FATAL1("Failed to get thread koid: %s\n", mx_status_get_string(status));
   }
   return info.koid;
 }
 
 
 #ifndef PRODUCT
 ThreadId OSThread::GetCurrentThreadTraceId() {
   return pthread_self();
 }
@@ skipping 257 matching lines @@
 void Monitor::NotifyAll() {
   // When running with assertions enabled we track the owner.
   ASSERT(IsOwnedByCurrentThread());
   int result = pthread_cond_broadcast(data_.cond());
   VALIDATE_PTHREAD_RESULT(result);
 }
 
 }  // namespace dart
 
 #endif  // defined(HOST_OS_FUCHSIA)