[lldb][NFCI] Remove use of ConstString from OptionValue

[bulbazord]

Summary

No need to create a ConstString, GetName already returns a StringRef.

[bulbazord]

Small fix

[jasonmolenda]

LGTM.

lldb/source/Interpreter/OptionValue.cpp

 
 bool OptionValue::DumpQualifiedName(Stream &strm) const {
   bool dumped_something = false;
   lldb::OptionValueSP m_parent_sp(m_parent_wp.lock());
   if (m_parent_sp) {
     if (m_parent_sp->DumpQualifiedName(strm))
       dumped_something = true;
   }
-  ConstString name(GetName());
-  if (name) {
+  llvm::StringRef name(GetName());
+  if (!name.empty()) {
     if (dumped_something)
       strm.PutChar('.');
     else
       dumped_something = true;
     strm << name;
   }
   return dumped_something;
 }