livepatch: match return value to function signature

klp_initialized() should return bool but is actually returning
struct kobject * - convert it to a boolean explicitly.

Signed-off-by: Nicholas Mc Guire <hofrat@osadl.org>
Reviewed-by: Jiri Slaby <jslaby@suse.cz>
Acked-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>