af_econet: Use current logging styles and neatening

Use pr_fmt() without KBUILD_MODNAME to allow AUN and econet prefixes.
Convert printks with KERN_DEBUG to pr_debug.
Hoist assigns from if.
80 column wrapping.
Move open braces to end of line.
Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: David S. Miller <davem@davemloft.net>