module: ensure that kobject_put() is safe for module type kobjects

In the Linux kernel, the following vulnerability has been resolved:

module: ensure that kobject_put() is safe for module type kobjects

In 'lookup_or_create_module_kobject()', an internal kobject is created

using 'module_ktype'. So call to 'kobject_put()' on error handling

path causes an attempt to use an uninitialized completion pointer in

'module_kobject_release()'. In this scenario, we just want to release

kobject without an extra synchronization required for a regular module

unloading process, so adding an extra check whether 'complete()' is

actually required makes 'kobject_put()' safe.