checkpatch: update suggested printk conversions

Direct conversion of printk(KERN_<LEVEL>...  to pr_<level> isn't the
preferred conversion when a struct net_device or struct device is
available.

Hint that using netdev_<level> or dev_<level> is preferred to using
pr_<level>.  Add netdev_dbg and dev_dbg variants too.

Miscellaneous whitespace neatening of a misplaced close brace.

Signed-off-by: Joe Perches <joe@perches.com>
Cc: Andy Whitcroft <apw@canonical.com>
Cc: Greg KH <gregkh@linuxfoundation.org>
Cc: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>