vyos.ethtool: T6070: fix EEE reading the incorrect status line

EEE enabled status is on the 2nd line of ethtool output and not the 3rd. Subsequently, reading the 3rd line was causing an out-of-bounds access for the bnx2x driver as well.

(cherry picked from commit 775348a4cda34e6be16454d43c77b525e57c4e47)