sfc: Fix some formatting errors reported by checkpatch

Fix the following errors and warnings:

ERROR: trailing whitespace
ERROR: spaces required around that '=' (ctx:VxV)
WARNING: please, no space before tabs

Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
diff --git a/drivers/net/ethernet/sfc/falcon_xmac.c b/drivers/net/ethernet/sfc/falcon_xmac.c
index 9516452..5743459 100644
--- a/drivers/net/ethernet/sfc/falcon_xmac.c
+++ b/drivers/net/ethernet/sfc/falcon_xmac.c
@@ -139,7 +139,7 @@
 	return (efx->loopback_mode == LOOPBACK_XGMII ||
 		falcon_xgxs_link_ok(efx)) &&
 		(!(efx->mdio.mmds & (1 << MDIO_MMD_PHYXS)) ||
-		 LOOPBACK_INTERNAL(efx) || 
+		 LOOPBACK_INTERNAL(efx) ||
 		 efx_mdio_phyxgxs_lane_sync(efx));
 }