qtdemux: fix conditions for end of segment in reverse playback

The time_position field of the stream is offset by the media_start
of its QtDemuxSegment compared to the start of the GstSegment of
the demuxer, take it into account when making comparisons.
22 jobs for qtdemux-fix-reverse-playback in 63 minutes and 44 seconds (queued for 7 minutes and 5 seconds)
Status Job ID Name Coverage
  Preparation
passed #410450
gst indent

00:00:30

passed #410449
manifest

00:00:42

 
  Build
passed #410456
build cerbero android universal

00:19:28

passed #410457
build cerbero cross win32

00:07:48

passed #410458
build cerbero cross win64

00:09:09

passed #410455
build cerbero fedora x86_64

00:08:59

manual #410460
gst-ios-12.2 allowed to fail manual
build cerbero ios universal
passed #410459
gst-macos-10.14
build cerbero macos x86_64

00:06:39

passed #410451
build fedora x86_64

00:09:30

passed #410452
build nodebug fedora x86_64

00:07:56

passed #410453
build static fedora x86_64

00:15:45

passed #410454
build static nodebug fedora x86_64

00:09:32

 
  Test
passed #410461
check fedora

00:05:59

passed #410462
integration testsuites fedora

00:09:47

passed #410464
valgrind bad

00:10:23

passed #410465
valgrind ges

00:06:33

passed #410956
valgrind good

00:07:07

failed #410561
valgrind good

00:18:46

passed #410560
valgrind good

00:09:26

failed #410463
valgrind good

00:18:43

 
  Integrate
passed #410466
android universal examples

00:07:07

passed #410467
documentation

00:05:24