This fixes a memory leak where the percpu internal structure is not freed. 
Repeated add/remove device illustrates the leak nicely.
Signed-off-by: Philip R. Auld <pauld@egenera.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>