Fix Clang-tidy readability-redundant-string-cstr warnings

Reviewers: zturner, labath

Subscribers: tberghammer, danalbert, lldb-commits
    
Differential Revision: https://reviews.llvm.org/D26233

llvm-svn: 285855
diff --git a/lldb/source/Interpreter/OptionValueFileSpec.cpp b/lldb/source/Interpreter/OptionValueFileSpec.cpp
index 732bafe..479d57e 100644
--- a/lldb/source/Interpreter/OptionValueFileSpec.cpp
+++ b/lldb/source/Interpreter/OptionValueFileSpec.cpp
@@ -77,7 +77,7 @@
       // or whitespace.
       value = value.trim("\"' \t");
       m_value_was_set = true;
-      m_current_value.SetFile(value.str().c_str(), m_resolve);
+      m_current_value.SetFile(value.str(), m_resolve);
       m_data_sp.reset();
       m_data_mod_time.Clear();
       NotifyValueChanged();