avwait: Don't post messages with the mutex locked

Part-of: <gstreamer/gst-plugins-bad!2068>
29 jobs for !2068 with backport-mr-2063-into-1.18-avwait-message-with-mutex in 32 minutes and 47 seconds (queued for 2 seconds)
detached
Status Job ID Name Coverage
  Build Docker
passed #7876455
alpine amd64 manifest builder docker

00:00:22

passed #7876454
android docker

00:00:49

passed #7876453
cerbero fedora amd64 docker

00:00:24

passed #7876452
fedora amd64 docker

00:00:39

passed #7876456
gst-indent amd64 docker

00:00:25

 
  Preparation
passed #7876458
gst indent

00:00:15

passed #7876457
manifest

00:00:48

 
  Build
passed #7876467
gstreamer
build cerbero cross-android universal

00:06:58

passed #7876471
gst-ios-14.3
build cerbero cross-ios universal

00:26:31

passed #7876468
gstreamer
build cerbero cross win32

00:05:05

passed #7876469
gstreamer
build cerbero cross win64

00:04:25

passed #7876466
gstreamer
build cerbero fedora x86_64

00:04:24

passed #7876470
gst-macos-11.1
build cerbero macos x86_64

00:12:30

passed #7876462
build clang fedora x86_64

00:06:41

manual #7876465
docker windows 1809 allowed to fail manual
build msys2
passed #7876459
build nodebug fedora x86_64

00:04:14

passed #7876460
build static fedora x86_64

00:09:16

passed #7876461
build static nodebug fedora x86_64

00:03:40

passed #7876463
docker windows 1809
build vs2017 amd64

00:08:42

passed #7876464
docker windows 1809
build vs2017 x86

00:08:53

 
  Test
passed #7876472
gstreamer
check fedora

00:06:08

passed #7876473
gstreamer
integration testsuites fedora 1/4

00:12:58

passed #7876474
gstreamer
integration testsuites fedora 2/4

00:13:48

passed #7876475
gstreamer
integration testsuites fedora 3/4

00:13:09

passed #7876476
gstreamer
integration testsuites fedora 4/4

00:15:18

passed #7876477
gstreamer
valgrind bad

00:05:29

 
  Integrate
passed #7876478
cross-android universal examples

00:06:41

passed #7876480
gst-ios-14.3
cross-ios universal examples

00:04:29

passed #7876479
documentation

00:13:56