Video format was treated as audio when removed from the file playback scheduler

Video format was treated as audio when removed from the file playback scheduler

This patch fixes the format type check in ast_closestream and
filestream_destructor.  Previously a comparison operator was used, but since
audio formats are no longer contiguous (and AST_FORMAT_AUDIO_MASK includes
formats that have a value greater than the video formats), a bitwise AND
operation is used instead.  Duplicated code was also moved to filestream_close.

(closes issue ASTERISK-18682)
Reported by: Aldo Bedrij
Tested by: Matt Jordan

Review: https://reviewboard.asterisk.org/r/1580/
........

Merged revisions 344823 from http://svn.asterisk.org/svn/asterisk/branches/1.8

git-svn-id: https://origsvn.digium.com/svn/asterisk/branches/10@344842 65c4cc65-6c06-0410-ace0-fbb531ad65f3