Merge some little changes from team/russell/chan_refcount to help reduce

the diff to trunk.

This just removes some checks on the return value of alloca(), as behavior
is undefined if it runs out of stack space, and we don't check it anywhere else.


git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@89947 65c4cc65-6c06-0410-ace0-fbb531ad65f3