page-types: whitespace alignment

Align the output when page-type -h is invoked.
Signed-off-by: NAlex Chiang <achiang@hp.com>
Acked-by: NWu Fengguang <fengguang.wu@intel.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>