yocto.groovy: remove use of named arguments when calling buildManifest()
yocto.groovy: remove use of named arguments when calling buildManifest()

Apparently named arguments do not work when Jenkins runs the Groovy code
in a JenkinsFile. The values that gets passed are null. Named arguments
work as expected when used in the script console ("Manage Jenkins" ->
"Script Console") though. No idea why.

Fixes building of meta-pelux that calls buildWithLayer() in its
JenkinsFile. Example of error output without this fix:

[intel-qtauto] [pelux-manifests] Running shell script
[intel-qtauto] + vagrant ssh -c rm -rf /vagrant/pelux_yocto/sources/null
[Pipeline] [intel-qtauto] sh
[intel-qtauto] [pelux-manifests] Running shell script
[intel-qtauto] + cp -R null null
[intel-qtauto] cp: cannot stat 'null': No such file or directory

Signed-off-by: Martin Ejdestig <6245dcb10f19f01f215dad2c1bc577b6938fd827@luxoft.com>

Pelagicore/pelux-manifests,sashko/pelux-manifests