DRIVERS: net: macsec: Fix multiple coding style issues

This patch fixes a couple of issues highlighted by checkpatch.pl:

    * Missing a blank line after declarations
    * Alignment should match open parenthesis

Signed-off-by: Romain Aviolat <r.aviolat@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>