Fix more memory leaks

Fix more memory leaks

This patch adds to what was fixed in r366880.  Specifically, it addresses the
following:

* chan_sip:  dispose of an allocated frame in off nominal code paths in
             sip_rtp_read
* func_odbc: when disposing of an allocated resultset, ensure that any rows
             that were appended to that resultset are also disposed of
* cli:       free the created return string buffer in another off nominal code
             path

(issue ASTERISK-19665)
Reported by: Matt Jordan

Review: https://reviewboard.asterisk.org/r/1922/

git-svn-id: https://origsvn.digium.com/svn/asterisk/branches/1.8@366944 65c4cc65-6c06-0410-ace0-fbb531ad65f3