Gcc4 doesn't like volatile casts as lvalues.  Make the structure members
volatile instead.
Signed-off-by: NDave Jones <davej@redhat.com>
Cc: "Luck, Tony" <tony.luck@intel.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>