fix doxygen brief in subzero header files

src/IceELFSection.cpp

 //===- subzero/src/IceELFSection.cpp - Representation of ELF sections -----===//
 //
 //                        The Subzero Code Generator
 //
 // This file is distributed under the University of Illinois Open Source
 // License. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 ///
 /// \file
-/// This file defines how ELF sections are represented.
+/// \brief Defines how ELF sections are represented.
 ///
 //===----------------------------------------------------------------------===//
 
 #include "IceELFSection.h"
 
 #include "IceDefs.h"
 #include "IceELFStreamer.h"
 #include "llvm/Support/MathExtras.h"
 
 using namespace llvm::ELF;
@@ skipping 197 matching lines @@
       continue;
     }
     StringIndex.second = StringData.size();
     std::copy(Cur.begin(), Cur.end(), back_inserter(StringData));
     StringData.push_back(0);
     Prev = Cur;
   }
 }
 
 } // end of namespace Ice