basetsmux: make use of gst_aggregator_finish_buffer_list

Fixes #1276

Part-of: <!1429>
29 jobs for master in 58 seconds (queued for 13 seconds)
Status Job ID Name Coverage
  Build Docker
passed #3562173
alpine amd64 manifest builder docker

00:00:34

passed #3562172
android docker

00:00:19

passed #3562171
cerbero fedora amd64 docker

00:00:31

passed #3562170
fedora amd64 docker

00:00:33

passed #3562174
gst-indent amd64 docker

00:00:33

 
  Preparation
passed #3562176
gst indent

00:00:24

manual #3562175
manual
manifest
 
  Build
created #3562185
gstreamer
build cerbero cross-android universal
created #3562194
gst-ios-13.2
build cerbero cross-ios universal
created #3562186
gstreamer
build cerbero cross win32
created #3562188
gstreamer
build cerbero cross win64
created #3562184
gstreamer
build cerbero fedora x86_64
created #3562191
gst-macos-10.15
build cerbero macos x86_64
created #3562180
build clang fedora x86_64
created #3562183
1809 windows docker allowed to fail manual
build msys2
created #3562177
build nodebug fedora x86_64
created #3562178
build static fedora x86_64
created #3562179
build static nodebug fedora x86_64
created #3562181
1809 windows docker
build vs2017 amd64
created #3562182
1809 windows docker
build vs2017 x86
 
  Test
created #3562196
gstreamer
check fedora
created #3562199
gstreamer
integration testsuites fedora 1/4
created #3562201
gstreamer
integration testsuites fedora 2/4
created #3562203
gstreamer
integration testsuites fedora 3/4
created #3562206
gstreamer
integration testsuites fedora 4/4
created #3562208
gstreamer
valgrind bad
 
  Integrate
created #3562209
cross-android universal examples
created #3562212
gst-ios-13.2
cross-ios universal examples
created #3562211
documentation