v4l2videodec: Fix drain() function return type

Return right type for drain() function.
18 jobs for debug in 49 minutes and 16 seconds (queued for 3 seconds)
Status Job ID Name Coverage
  Preparation
passed #355379
gst indent

00:00:16

passed #355378
manifest

00:00:41

 
  Build
passed #355380
build fedora x86_64

00:08:57

passed #355381
build nodebug fedora x86_64

00:07:33

passed #355382
build static fedora x86_64

00:15:08

passed #355383
build static nodebug fedora x86_64

00:09:41

 
  Test
passed #355384
check fedora

00:03:33

passed #355385
integration testsuites fedora

00:09:47

 
  Full Builds
passed #355387
build cerbero android universal

00:21:51

passed #355388
build cerbero cross win32

00:17:42

passed #355389
build cerbero cross win64

00:14:43

passed #355386
build cerbero fedora x86_64

00:13:45

passed #355390
gst-macos-10.14
build cerbero macos x86_64

00:08:41

 
  Full Tests
failed #355392
valgrind bad

00:01:43

failed #355393
valgrind ges

00:01:45

failed #355391
valgrind good

00:01:45

 
  Apps
skipped #355394
android universal examples
 
  Deploy
skipped #355395
documentation
 
Name Stage Failure
failed
valgrind ges Full Tests
TypeError: 'NoneType' object is not subscriptable
Uploading artifacts...
gst-build/build/meson-logs/: found 2 matching files
validate-logs: found 3 matching files
Uploading artifacts to coordinator... ok id=355393 responseStatus=201 Created token=iSejRMVT
Uploading artifacts...
WARNING: validate-logs/*.xml: no matching files
ERROR: No files to upload
ERROR: Job failed: exit code 1
failed
valgrind good Full Tests
TypeError: 'NoneType' object is not subscriptable
Uploading artifacts...
gst-build/build/meson-logs/: found 2 matching files
validate-logs: found 3 matching files
Uploading artifacts to coordinator... ok id=355391 responseStatus=201 Created token=wxwqfM84
Uploading artifacts...
WARNING: validate-logs/*.xml: no matching files
ERROR: No files to upload
ERROR: Job failed: exit code 1
failed
valgrind bad Full Tests
TypeError: 'NoneType' object is not subscriptable
Uploading artifacts...
gst-build/build/meson-logs/: found 2 matching files
validate-logs: found 3 matching files
Uploading artifacts to coordinator... ok id=355392 responseStatus=201 Created token=8AukzPrT
Uploading artifacts...
WARNING: validate-logs/*.xml: no matching files
ERROR: No files to upload
ERROR: Job failed: exit code 1