mm, memory_hotplug: replace for_device by want_memblock in arch_add_memory

mm, memory_hotplug: replace for_device by want_memblock in arch_add_memory

arch_add_memory gets for_device argument which then controls whether we
want to create memblocks for created memory sections.  Simplify the
logic by telling whether we want memblocks directly rather than going
through pointless negation.  This also makes the api easier to
understand because it is clear what we want rather than nothing telling
for_device which can mean anything.

This shouldn't introduce any functional change.

Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Michal Hocko <[email protected]>
Tested-by: Dan Williams <[email protected]>
Acked-by: Vlastimil Babka <[email protected]>
Cc: Andi Kleen <[email protected]>
Cc: Andrea Arcangeli <[email protected]>
Cc: Balbir Singh <[email protected]>
Cc: Daniel Kiper <[email protected]>
Cc: David Rientjes <[email protected]>
Cc: Heiko Carstens <[email protected]>
Cc: Igor Mammedov <[email protected]>
Cc: Jerome Glisse <[email protected]>
Cc: Joonsoo Kim <[email protected]>
Cc: Martin Schwidefsky <[email protected]>
Cc: Mel Gorman <[email protected]>
Cc: Reza Arbab <[email protected]>
Cc: Tobias Regnery <[email protected]>
Cc: Toshi Kani <[email protected]>
Cc: Vitaly Kuznetsov <[email protected]>
Cc: Xishi Qiu <[email protected]>
Cc: Yasuaki Ishimatsu <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>