sfc: falcon: remove duplicated bit-wise or of LOOPBACK_SGMII

Bit pattern LOOPBACK_SGMII is being bit-wise or'd twice; remove the
redundant 2nd LOOPBACK_SGMII
Signed-off-by: NColin Ian King <colin.king@canonical.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

drivers/net/ethernet/sfc/falcon/enum.h

@@ -81,7 +81,6 @@ enum ef4_loopback_mode {
 			    (1 << LOOPBACK_XAUI) |		\
 			    (1 << LOOPBACK_GMII) |		\
 			    (1 << LOOPBACK_SGMII) |		\
-			    (1 << LOOPBACK_SGMII) |		\
 			    (1 << LOOPBACK_XGBR) |		\
 			    (1 << LOOPBACK_XFI) |		\
 			    (1 << LOOPBACK_XAUI_FAR) |		\