cmGeneratedFileStream: clang-tidy applied to remove redundant ``c_str`` calls

After changing the ``cmGeneratedFileStream`` methods to accept
``std::string const&`` instead of ``const char*`` we don't
need to call ``std::string::c_str`` anymore when passing
a ``std::string`` to a ``cmGeneratedFileStream`` method.

This patch removes all redundant ``std::string::c_str``
calls when passing a string to a ``cmGeneratedFileStream`` method.

It was generated by building CMake with clang-tidy enabled using
the following options:

-DCMAKE_CXX_CLANG_TIDY=/usr/bin/clang-tidy-4.0;-checks=-*,readability-redundant-string-cstr;-fix;-fix-errors

1 files changed, 1 insertions, 1 deletions

diff --git a/Source/cmGeneratorExpressionEvaluationFile.cxx b/Source/cmGeneratorExpressionEvaluationFile.cxx
index 99b9261..a094fa5 100644
--- a/Source/cmGeneratorExpressionEvaluationFile.cxx
+++ b/Source/cmGeneratorExpressionEvaluationFile.cxx
@@ -85,7 +85,7 @@ void cmGeneratorExpressionEvaluationFile::Generate(
   this->Files.push_back(outputFileName);
   outputFiles[outputFileName] = outputContent;
 
-  cmGeneratedFileStream fout(outputFileName.c_str());
+  cmGeneratedFileStream fout(outputFileName);
   fout.SetCopyIfDifferent(true);
   fout << outputContent;
   if (fout.Close() && perm) {