ice: downgrade error print to debug print

Failing to add or remove LLDP filter doesn't seem to be a fatal
error, so downgrade the dev_err message to a dev_dbg message.

Signed-off-by: Anirudh Venkataramanan <anirudh.venkataramanan@intel.com>
Tested-by: Tony Brelinski <tonyx.brelinski@intel.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>