The comment in find_fstype_by_name() says:

	just mounting anything is wrong

and this is true in general, but:

	almost every fs has its own features

this is not true in a sense that a lot of supported filesystems do not
need any special processing: FSTYPE__PROC, FSTYPE__SYSFS, and more. More
importantly, this logic does not allow to spicify from the command line
that (say) currently unsupported hugetlbfs can "just work", do_new_mount()
should only pass the right name/options.

This patch adds the new FSTYPE__AUTO code, find_fstype_by_name(name) adds
the new entry if fsname_is_auto(name) returns true. We do not care that
different fstype's can have the same FSTYPE__AUTO code, fstype->code has
no meaning unless we need to do something special with this fs, but in
this case it should not be FSTYPE__AUTO by definition.

Note: currently find_fstype_by_name() just returns true, it is obviously
pointless to "dump" until we teach "restore" to handle FSTYPE__AUTO.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>