fix doxygen brief in subzero header files

src/IceTLS.h

Index: src/IceTLS.h
diff --git a/src/IceTLS.h b/src/IceTLS.h
index 5b9a8e8b0ddfbf5ee66cc4e6ba2068a13848da50..73d75049867c705f2f43f01905f8f80a5f3598d8 100644
--- a/src/IceTLS.h
+++ b/src/IceTLS.h
@@ -8,9 +8,11 @@
 //===----------------------------------------------------------------------===//
 ///
 /// \file
-/// This file defines macros for working around the lack of support for
-/// thread_local in MacOS 10.6. It assumes std::thread is written in terms of
-/// pthread. Define ICE_THREAD_LOCAL_HACK to enable the pthread workarounds.
+/// \brief Defines macros for working around the lack of support for
+/// thread_local in MacOS 10.6.
+///
+/// This assumes std::thread is written in terms of pthread. Define
+/// ICE_THREAD_LOCAL_HACK to enable the pthread workarounds.
 ///
 //===----------------------------------------------------------------------===//