Fix ast_writestream leaks

Fix cleanup in __ast_play_and_record where others[x] may be leaked.
This was caught where prepend != NULL && outmsg != NULL, once
realfile[x] == NULL any further others[x] would be leaked. A cleanup
block was also added for prepend != NULL && outmsg == NULL.

11+: Fix leak of ast_writestream recording_fs in
app_voicemail:leave_voicemail.

ASTERISK-24476 #close
Reported by: Corey Farrell
Review: https://reviewboard.asterisk.org/r/4138/
........

Merged revisions 427023 from http://svn.asterisk.org/svn/asterisk/branches/1.8
........

Merged revisions 427024 from http://svn.asterisk.org/svn/asterisk/branches/11
........

Merged revisions 427025 from http://svn.asterisk.org/svn/asterisk/branches/12


git-svn-id: http://svn.asterisk.org/svn/asterisk/branches/13@427026 f38db490-d61c-443f-a65b-d21fe96a405b