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/ethtool.c b/drivers/net/ethernet/sfc/ethtool.c
index 29b2ebf..c090de4 100644
--- a/drivers/net/ethernet/sfc/ethtool.c
+++ b/drivers/net/ethernet/sfc/ethtool.c
@@ -68,11 +68,11 @@
 }
 
 #define EFX_ETHTOOL_ULONG_MAC_STAT(field)			\
-	EFX_ETHTOOL_STAT(field, mac_stats, field, 		\
+	EFX_ETHTOOL_STAT(field, mac_stats, field,		\
 			  unsigned long, efx_get_ulong_stat)
 
 #define EFX_ETHTOOL_U64_MAC_STAT(field)				\
-	EFX_ETHTOOL_STAT(field, mac_stats, field, 		\
+	EFX_ETHTOOL_STAT(field, mac_stats, field,		\
 			  u64, efx_get_u64_stat)
 
 #define EFX_ETHTOOL_UINT_NIC_STAT(name)				\