bugtool: remove empty directories
bugtool: remove empty directories

Only the top level ones. In case nested directories have meaning for
debugging leaving them as is.

Closes: #2401 (bugtool: trim empty directories)

Signed-off-by: Alexander Alemayhu <e46fc836cca3acec03944314d1457c2ae6c68ef3@alemayhu.com>

tklauser/cilium,tgraf/cilium,cilium/cilium,michi-covalent/cilium,scanf/cilium,tklauser/cilium,cilium-team/cilium,tgraf/cilium,scanf/cilium,michi-covalent/cilium,michi-covalent/cilium,cilium/cilium,eloycoto/cilium,cilium/cilium,scanf/cilium,scanf/cilium,michi-covalent/cilium,tklauser/cilium,cilium/cilium,cilium/cilium,michi-covalent/cilium,scanf/cilium,cilium-team/cilium,eloycoto/cilium,tklauser/cilium,eloycoto/cilium,eloycoto/cilium,eloycoto/cilium,scanf/cilium,tgraf/cilium,tklauser/cilium,tgraf/cilium,eloycoto/cilium,tgraf/cilium,scanf/cilium,eloycoto/cilium,tgraf/cilium