I believe this makes it a little more clear what is happening. Also could
provide a potential speedup if the span doesn't need to be constantly
dereferenced (although an optimizer might make this moot). Regardless, this
change doesn't hurt.
Review: https://reviewboard.asterisk.org/r/905/
Signed-off-by: Shaun Ruffell <sruffell@digium.com>
git-svn-id: http://svn.asterisk.org/svn/dahdi/linux/trunk@9362 a0bf4364-ded3-4de4-8d8a-66a801d63aff