livepatch-build: Strip transient or unneeded symbols

livepatch-build: Strip transient or unneeded symbols

In the process of creating a final hotpatch module file make sure to
strip all transient symbols that have not been caught and removed by
create-diff-object processing. For now these are only the hooks
kpatch load/unload symbols.

For all new object files that are carried along for the final linking
the transient hooks symbols are not stripped and neither are any
unneeded symbols. Strip the transient hooks symbols explicitly from
resulting object file.
Add a new option '--strip' to additionally strip all unneeded symbols
from new object files.

Signed-off-by: Pawel Wieczorkiewicz <wipawel@amazon.de>
Reviewed-by: Ross Lagerwall <ross.lagerwall@citrix.com>
Signed-off-by: Ross Lagerwall <ross.lagerwall@citrix.com>