net-sysfs: fix netdev_queue_add_kobject() breakage

kobject_put() should only be called in error path.

Fixes: b8eb7183 ("net-sysfs: Fix reference count leak in rx|netdev_queue_add_kobject")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Jouni Hogander <jouni.hogander@unikie.com>
Signed-off-by: David S. Miller <davem@davemloft.net>