x86/mm/init.c: Fix devmem_is_allowed() off by one

x86/mm/init.c: Fix devmem_is_allowed() off by one

commit 73e8f3d7e2cb23614d5115703d76d8e54764b641 upstream.

Fixing an off-by-one error in devmem_is_allowed(), which allows
accesses to physical addresses 0x100000-0x100fff, an extra page
past 1MB.

Signed-off-by: T Makphaibulchoke <tmac@hp.com>
Acked-by: H. Peter Anvin <hpa@zytor.com>
Cc: yinghai@kernel.org
Cc: tiwai@suse.de
Cc: dhowells@redhat.com
Link: http://lkml.kernel.org/r/1346210503-14276-1-git-send-email-tmac@hp.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>