fix doxygen brief in subzero header files

src/IceRNG.cpp

 //===- subzero/src/IceRNG.cpp - PRNG implementation -----------------------===//
 //
 //                        The Subzero Code Generator
 //
 // This file is distributed under the University of Illinois Open Source
 // License. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 ///
 /// \file
-/// This file implements the random number generator.
+/// \brief Implements the random number generator.
 ///
 //===----------------------------------------------------------------------===//
 
 #include "IceRNG.h"
 
 #include <ctime>
 
 namespace Ice {
 
 namespace {
@@ skipping 23 matching lines @@
   // Lewis, Goodman, and Miller (1969)
   State = (16807 * State) % MAX;
   return State % Max;
 }
 
 bool RandomNumberGeneratorWrapper::getTrueWithProbability(float Probability) {
   return RNG.next(MAX) < Probability * MAX;
 }
 
 } // end of namespace Ice