staging: rtl8192u: Replace printk() with more standardize output format.

printk() is the raw way to print output and should be avoided.

For drivers with defined "struct device object", dev_*macro() is
prefer and for "struct netdevice object", netdev_*macro() is prefer over
dev_*macro() to standardize the output format within the subsystem.

If no "struct device object" is defined prefer pr_*macro() over printk().

This patch Replace printk having a log level with the appropriate output
format according to the order of preference.

Signed-off-by: Arushi Singhal <arushisinghal19971997@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>