[lldb-mi] Remove unnecessary const_cast.

Summary: Remove unnecessary const_cast.

Reviewers: abidh, ki.stfu

Subscribers: lldb-commits

Differential Revision: http://reviews.llvm.org/D10928

llvm-svn: 241359

lldb/tools/lldb-mi/MICmdArgValFile.cpp

@@ -182,7 +182,7 @@ bool
 CMICmdArgValFile::IsValidChars(const CMIUtilString &vrText) const
 {
     static CMIUtilString s_strSpecialCharacters(".'\"`@#$%^&*()_+-={}[]| ");
-    const char *pPtr = const_cast<char *>(vrText.c_str());
+    const char *pPtr = vrText.c_str();
     for (MIuint i = 0; i < vrText.length(); i++, pPtr++)
     {
         const char c = *pPtr;