mlaudiosink: Fix crash when stopping pipeline

This is a bug in LuminOS 0.97.0.
22 jobs for mlaudiosink in 44 minutes and 15 seconds (queued for 4 seconds)
latest
Status Job ID Name Coverage
  Preparation
passed #912883
gst indent

00:00:44

passed #912882
manifest

00:00:40

 
  Build
passed #912893
build cerbero cross-android universal

00:12:30

manual #912897
gst-ios-12.2 allowed to fail manual
build cerbero cross-ios universal
passed #912894
build cerbero cross win32

00:09:28

passed #912895
build cerbero cross win64

00:08:31

passed #912892
build cerbero fedora x86_64

00:08:33

passed #912896
gst-macos-10.14
build cerbero macos x86_64

00:06:40

passed #912888
build clang fedora x86_64

00:09:29

passed #912884
build fedora x86_64

00:06:13

passed #912891
docker windows 1607
build msys2

00:12:37

passed #912885
build nodebug fedora x86_64

00:03:13

passed #912886
build static fedora x86_64

00:12:30

passed #912887
build static nodebug fedora x86_64

00:05:11

passed #912889
docker windows 1607
build vs2017 amd64

00:10:18

passed #912890
docker windows 1607
build vs2017 x86

00:11:03

 
  Test
failed #912898
gstreamer
check fedora

00:03:47

passed #912899
gstreamer
integration testsuites fedora

00:37:17

passed #912900
gstreamer
valgrind bad

00:07:24

 
  Integrate
passed #912901
cross-android universal examples

00:04:54

skipped #912903
gst-ios-12.2 allowed to fail manual
cross-ios universal examples
passed #912902
documentation

00:03:51

 
Name Stage Failure
failed
check fedora Test
!! Could not derive your terminal width !!
Uploading artifacts...
gst-build/build/meson-logs/: found 2 matching files
validate-logs: found 3582 matching files

Uploading artifacts to coordinator... ok
id=912898 responseStatus=201 Created token=5y4rz9Qz
Uploading artifacts...
validate-logs/*.xml: found 1 matching files

Uploading artifacts to coordinator... ok
id=912898 responseStatus=201 Created token=5y4rz9Qz
ERROR: Job failed: exit code 1