staging: r8723au: replace printk() with netdev_err()

Replace printk() with netdev_err() for uniform error reporting.
Issue found by checkpatch.

Signed-off-by: Alison Schofield <amsfield22@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
1 file changed