Revert "For livebuild we have (like kiwi) sub-directories with additional packages in the source folder"

This reverts commit 758824d36df2b5103f842bbe4804bdb6b6cc95e8.
livebuild: Remove another left-over when using the repos sub-directory

This is removing another code section that is not required anymore since we
are using the /.build.binaries folder instead.

Signed-off-by: Jan Blunck <jblunck@infradead.org>