fix package detection

ubuntu-kernel-cleanup.py

@@ -48,7 +48,7 @@ def get_packages_list(pkg_match):
     installed_list = installed_out.decode('utf-8').split('\n')
     # delete empty items
     kernels = [item for item in installed_list if item != '']
-    kernel_versions = [item.replace(pkg_match, '') for item in kernels]
+    kernel_versions = [get_version(item) for item in kernels]
     # sort by version and unique
     return sorted(list(set(kernel_versions)), key=LooseVersion)