This patch is needed since "warning: use of cast expressions as lvalues is
deprecated" turned into an error in gcc4.  We can use the convenience macros
for read access and explicit assignments for initialization.  I thought about
using Alexandre's fixes, but this seemed a little simpler.
Signed-off-by: Jesse Barnes <jbarnes@sgi.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>