package.bbclass: Remove empty directories created as part of srcdebug handling
We can create directories like /usr/src/debug as part of the debug file
manipulations. If these are going to end up empty, remove them to avoid QA
warnings like:
WARNING: For recipe task-core-x11, the following files/directories were installed but not shipped in any package:
WARNING: /usr
WARNING: /usr/src
WARNING: /usr/src/debug
WARNING: For recipe task-core-console, the following files/directories were installed but not shipped in any package:
WARNING: /usr
WARNING: /usr/src
WARNING: /usr/src/debug
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
