Add a missing Mutex Locker in ResetCurrentInlinedDepth

Summary: This function reads m_frames, so it needs to lock the
mutex like all other function that access m_frames.
Found using AddressSanitizer.

Reviewers: jingham, clayborg

Subscribers: lldb-commits

Differential Revision: http://reviews.llvm.org/D13638

llvm-svn: 250493

lldb/source/Target/StackFrameList.cpp

@@ -105,6 +105,8 @@ StackFrameList::GetCurrentInlinedDepth ()
 void
 StackFrameList::ResetCurrentInlinedDepth ()
 {
+    Mutex::Locker locker (m_mutex);
+
     if (m_show_inlined_frames)
     {        
         GetFramesUpTo(0);