fix endianes issues in chan_skinny

(closes issue #16826)
Reported by: PipoCanaja
Patches: 
      chan_skinny.c_bigendianPatch_20100218.diff uploaded by PipoCanaja (license 994)
Tested by: wedhorn



git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@249669 65c4cc65-6c06-0410-ace0-fbb531ad65f3