sysfs: bugfix: shorten too long file names

* In old kernels (e.g: 2.6.18) sysfs file names must be shorter
  then KOBJ_NAME_LEN.

* Longer names are truncated and this leads to duplicate names
  which fails device_register()
  Examples: "dahdi!channels!10!10" is truncated to "dahdi!channels!10!1"

* The fix shorten the names and make them fixed length. Example:
            "dahdi!chan!010!010"

* It seems no current userspace tools rely on that name or on
  /dev/dahdi/channels .

Signed-off-by: Tzafrir Cohen <tzafrir.cohen@xorcom.com>
build_tools/make_version: Fix typo in build_tools/make_version.

The make_version script would test for a .version file in the proper location,
but then would not properly read it. Since make_version is always reading the
.version script correctly now, the Makefile can be slightly simpilfied and
always defer to it.

This has no user impact since build_tools/make_version was never used to read
the .version file previously but will allow external scripts to use the
make_version script.

Signed-off-by: Shaun Ruffell <sruffell@digium.com>
Signed-off-by: Russ Meyerriecks <rmeyerriecks@digium.com>