Kernel doesn't allow to read /proc/pid/map_files. This file
is used to get pseudo device for anon shmem mappings, but
this info can be get by scanning /proc/self/maps file.

This works slower, but still.
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
Looks-good-to-me: Andrew Vagin <avagin@virtuozzo.com>