Fix chan_dahdi copile issue in dev-mode.

Error "unused variable i in dahdi_create_channel_range" when compiling
in dev-mode. Small restructure to dahdi_create_channel_range to move 
the for(x) loop and int i,x to a block within the IFDEF.
........

Merged revisions 405268 from http://svn.asterisk.org/svn/asterisk/branches/12


git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@405269 65c4cc65-6c06-0410-ace0-fbb531ad65f3