cmake: Use scopes to limit temporary object lifetime

Source/cmake.cxx

@@ -2430,6 +2430,7 @@ static bool cmakeCheckStampFile(const std::string& stampName)
   }
 
   // Compare the stamp dependencies against the dependency file itself.
+  {
     cmFileTimeCache ftc;
     std::string dep;
     while (cmSystemTools::GetLineFromStream(fin, dep)) {
@@ -2446,6 +2447,7 @@ static bool cmakeCheckStampFile(const std::string& stampName)
         return false;
       }
     }
+  }
 
   // The build system is up to date.  The stamp file has been removed
   // by the VS IDE due to a "rebuild" request.  Restore it atomically.