x86/mm/init: Fix incorrect page size in init_memory_mapping() printks

With 32-bit non-PAE kernels, we have 2 page sizes available
(at most): 4k and 4M.

Enabling PAE replaces that 4M size with a 2M one (which 64-bit
systems use too).

But, when booting a 32-bit non-PAE kernel, in one of our
early-boot printouts, we say:

  init_memory_mapping: [mem 0x00000000-0x000fffff]
   [mem 0x00000000-0x000fffff] page 4k
  init_memory_mapping: [mem 0x37000000-0x373fffff]
   [mem 0x37000000-0x373fffff] page 2M
  init_memory_mapping: [mem 0x00100000-0x36ffffff]
   [mem 0x00100000-0x003fffff] page 4k
   [mem 0x00400000-0x36ffffff] page 2M
  init_memory_mapping: [mem 0x37400000-0x377fdfff]
   [mem 0x37400000-0x377fdfff] page 4k

Which is obviously wrong.  There is no 2M page available.  This
is probably because of a badly-named variable: in the map_range
code: PG_LEVEL_2M.

Instead of renaming all the PG_LEVEL_2M's.  This patch just
fixes the printout:

  init_memory_mapping: [mem 0x00000000-0x000fffff]
   [mem 0x00000000-0x000fffff] page 4k
  init_memory_mapping: [mem 0x37000000-0x373fffff]
   [mem 0x37000000-0x373fffff] page 4M
  init_memory_mapping: [mem 0x00100000-0x36ffffff]
   [mem 0x00100000-0x003fffff] page 4k
   [mem 0x00400000-0x36ffffff] page 4M
  init_memory_mapping: [mem 0x37400000-0x377fdfff]
   [mem 0x37400000-0x377fdfff] page 4k
  BRK [0x03206000, 0x03206fff] PGTABLE

Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Pekka Enberg <penberg@cs.helsinki.fi>
Cc: Yinghai Lu <yinghai@kernel.org>
Link: http://lkml.kernel.org/r/20150210212030.665EC267@viggo.jf.intel.com


Signed-off-by: Borislav Petkov <bp@suse.de>