chan_sip: Hangup transferer/transferee when transfer to Parking fails

chan_sip: Hangup transferer/transferee when transfer to Parking fails

When performing a SIP transfer to a Park extension, if the Park fails, chan_sip
will currently not hang up either the transferer or the transfer target. This
results in the channels being orphaned with no thread to service frames,
resulting in stuck channels.

This patch immediately hangs up the two channels if a Park fails.

(closes issue ASTERISK-22834)
Reported by: rsw686
Tested by: rsw686

(closes issue ASTERISK-23047)
Reported by: Tommy Thompson
Tested by: Tommy Thomspon

Review: https://reviewboard.asterisk.org/r/3107
........

Merged revisions 405380 from http://svn.asterisk.org/svn/asterisk/branches/11

git-svn-id: https://origsvn.digium.com/svn/asterisk/certified/branches/11.6@405536 65c4cc65-6c06-0410-ace0-fbb531ad65f3