staging/octeon:ethernet-rgmii.c: Fix line over 80 characters.

checkpatch.pl issues with line over
80 characters in ethernet-rgmii.c

Signed-off-by: Aybuke Ozdemir <aybuke.147@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>