Remove unused variable in src/platform-solaris.cc.

src/platform-solaris.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 469 matching lines @@
 }
 
 
 void Thread::set_name(const char* name) {
   strncpy(name_, name, sizeof(name_));
   name_[sizeof(name_) - 1] = '\0';
 }
 
 
 void Thread::Start() {
-  pthread_attr_t* attr_ptr = NULL;
   pthread_attr_t attr;
   if (stack_size_ > 0) {
     pthread_attr_init(&attr);
     pthread_attr_setstacksize(&attr, static_cast<size_t>(stack_size_));
-    attr_ptr = &attr;
   }
   pthread_create(&data_->thread_, NULL, ThreadEntry, this);
   ASSERT(data_->thread_ != kNoThread);
 }
 
 
 void Thread::Join() {
   pthread_join(data_->thread_, NULL);
 }
 
@@ skipping 390 matching lines @@
 }
 
 
 void Sampler::Stop() {
   ASSERT(IsActive());
   SignalSender::RemoveActiveSampler(this);
   SetActive(false);
 }
 
 } }  // namespace v8::internal