Staging: rtl8192u: ieee80211: Use netdev_info instead of printk

Replace printk with netdev_info because struct ieee80211_device
contains a net_device structure.

Issue found by checkpatch.pl script.
WARNING: Prefer [subsystem eg: netdev]_info([subsystem]dev, ... then
dev_info(dev, ... then pr_info(...  to printk(KERN_INFO ...

Signed-off-by: Georgiana Chelu <georgiana.chelu93@example.com>
Acked-by: Julia Lawall <julia.lawall@lip6.fr>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>