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

ConstString is simply not needed here.

Differential Revision: https://reviews.llvm.org/D152310

Author: bulbazord

lldb/source/Interpreter/OptionValueLanguage.cpp

@@ -43,10 +43,8 @@ Status OptionValueLanguage::SetValueFromString(llvm::StringRef value,
 
   case eVarSetOperationReplace:
   case eVarSetOperationAssign: {
-    ConstString lang_name(value.trim());
     LanguageSet languages_for_types = Language::GetLanguagesSupportingTypeSystems();
-    LanguageType new_type =
-        Language::GetLanguageTypeFromString(lang_name.GetStringRef());
+    LanguageType new_type = Language::GetLanguageTypeFromString(value.trim());
     if (new_type && languages_for_types[new_type]) {
       m_value_was_set = true;
       m_current_value = new_type;