ART: Clean up old mutex

Remove obsolete mutex.

Test: m test-art-host
Change-Id: I476792cac4d5d680192e35055abed66772cf8081
diff --git a/runtime/base/mutex.cc b/runtime/base/mutex.cc
index bde0327..5d92298 100644
--- a/runtime/base/mutex.cc
+++ b/runtime/base/mutex.cc
@@ -42,7 +42,6 @@
 ReaderWriterMutex* Locks::heap_bitmap_lock_ = nullptr;
 Mutex* Locks::instrument_entrypoints_lock_ = nullptr;
 Mutex* Locks::intern_table_lock_ = nullptr;
-Mutex* Locks::interpreter_string_init_map_lock_ = nullptr;
 Mutex* Locks::jni_libraries_lock_ = nullptr;
 Mutex* Locks::logging_lock_ = nullptr;
 Mutex* Locks::mem_maps_lock_ = nullptr;
diff --git a/runtime/base/mutex.h b/runtime/base/mutex.h
index 3f2c5a9..d81c66e 100644
--- a/runtime/base/mutex.h
+++ b/runtime/base/mutex.h
@@ -630,12 +630,9 @@
   // TODO: improve name, perhaps instrumentation_update_lock_.
   static Mutex* deoptimization_lock_ ACQUIRED_AFTER(alloc_tracker_lock_);
 
-  // Guards String initializer register map in interpreter.
-  static Mutex* interpreter_string_init_map_lock_ ACQUIRED_AFTER(deoptimization_lock_);
-
   // The thread_list_lock_ guards ThreadList::list_. It is also commonly held to stop threads
   // attaching and detaching.
-  static Mutex* thread_list_lock_ ACQUIRED_AFTER(interpreter_string_init_map_lock_);
+  static Mutex* thread_list_lock_ ACQUIRED_AFTER(deoptimization_lock_);
 
   // Signaled when threads terminate. Used to determine when all non-daemons have terminated.
   static ConditionVariable* thread_exit_cond_ GUARDED_BY(Locks::thread_list_lock_);