mm/memblock.c: reversed logic in memblock_discard()

mm/memblock.c: reversed logic in memblock_discard()

In recently introduced memblock_discard() there is a reversed logic bug.
Memory is freed of static array instead of dynamically allocated one.

Link: http://lkml.kernel.org/r/[email protected]
Fixes: 3010f876500f ("mm: discard memblock data later")
Signed-off-by: Pavel Tatashin <[email protected]>
Reported-by: Woody Suwalski <[email protected]>
Tested-by: Woody Suwalski <[email protected]>
Acked-by: Michal Hocko <[email protected]>
Cc: Vlastimil Babka <[email protected]>
Cc: <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>