When the SHARED function modifies a variable, it removes it from its list of
variables and reinserts the new value at the head of the list of variables.
Doing this inside a standard list traversal can be dangerous, as the
standard list traversal does not account for the list being changed. While
the code in question should not cause a use after free violation due to its
breaking out of the loop after freeing the variable, it could lead to a
maintenance issue if the loop was modified. This also fixes a violation
reported by a static analysis tool, which also makes this code easier to
maintain in the future.
git-svn-id: https://origsvn.digium.com/svn/asterisk/branches/1.8@361657 65c4cc65-6c06-0410-ace0-fbb531ad65f3