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, 2 insertions, 2 deletions

diff --git a/Source/cmGraphVizWriter.cxx b/Source/cmGraphVizWriter.cxx
index 1bbfbe0..fcdf03f 100644
--- a/Source/cmGraphVizWriter.cxx
+++ b/Source/cmGraphVizWriter.cxx
@@ -257,7 +257,7 @@ void cmGraphVizWriter::WriteTargetDependersFiles(const char* fileName)
     currentFilename += ptr.first;
     currentFilename += ".dependers";
 
-    cmGeneratedFileStream str(currentFilename.c_str());
+    cmGeneratedFileStream str(currentFilename);
     if (!str) {
       return;
     }
@@ -300,7 +300,7 @@ void cmGraphVizWriter::WritePerTargetFiles(const char* fileName)
     std::string currentFilename = fileName;
     currentFilename += ".";
     currentFilename += ptr.first;
-    cmGeneratedFileStream str(currentFilename.c_str());
+    cmGeneratedFileStream str(currentFilename);
     if (!str) {
       return;
     }