Fuchsia: fix Debug build

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(TARGET_OS_FUCHSIA)
 
 #include "vm/os_thread.h"
 #include "vm/os_thread_fuchsia.h"
 
@@ skipping 15 matching lines @@
 #define ASSERT_PTHREAD_SUCCESS(result) VALIDATE_PTHREAD_RESULT(result)
 #else
 // NOTE: This (currently) expands to a no-op.
 #define ASSERT_PTHREAD_SUCCESS(result) ASSERT(result == 0)
 #endif
 
 
 #ifdef DEBUG
 #define RETURN_ON_PTHREAD_FAILURE(result) \
   if (result != 0) { \
-    const int kBufferSize = 1024; \
-    char error_buf[kBufferSize]; \
     fprintf(stderr, "%s:%d: pthread error: %d\n", \
             __FILE__, __LINE__, result); \
     return result; \
   }
 #else
 #define RETURN_ON_PTHREAD_FAILURE(result) \
   if (result != 0) return result;
 #endif
 
 
@@ skipping 374 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(TARGET_OS_FUCHSIA)