drivers/base/memory.c: fix warning due to "memory hotplug: Speed up add/remove when blocks are larger than PAGES_PER_SECTION"

drivers/base/memory.c: In function 'memory_block_change_state':
drivers/base/memory.c:281: warning: unused variable 'i'

less beer, more testing

Cc: Anton Blanchard <anton@samba.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>