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/efx.c b/drivers/net/ethernet/sfc/efx.c
index e43702f..11cc585 100644
--- a/drivers/net/ethernet/sfc/efx.c
+++ b/drivers/net/ethernet/sfc/efx.c
@@ -44,9 +44,9 @@
 	[LOOPBACK_GMAC]		= "GMAC",
 	[LOOPBACK_XGMII]	= "XGMII",
 	[LOOPBACK_XGXS]		= "XGXS",
-	[LOOPBACK_XAUI]  	= "XAUI",
-	[LOOPBACK_GMII] 	= "GMII",
-	[LOOPBACK_SGMII] 	= "SGMII",
+	[LOOPBACK_XAUI]		= "XAUI",
+	[LOOPBACK_GMII]		= "GMII",
+	[LOOPBACK_SGMII]	= "SGMII",
 	[LOOPBACK_XGBR]		= "XGBR",
 	[LOOPBACK_XFI]		= "XFI",
 	[LOOPBACK_XAUI_FAR]	= "XAUI_FAR",
@@ -55,17 +55,17 @@
 	[LOOPBACK_XFI_FAR]	= "XFI_FAR",
 	[LOOPBACK_GPHY]		= "GPHY",
 	[LOOPBACK_PHYXS]	= "PHYXS",
-	[LOOPBACK_PCS]	 	= "PCS",
-	[LOOPBACK_PMAPMD] 	= "PMA/PMD",
+	[LOOPBACK_PCS]		= "PCS",
+	[LOOPBACK_PMAPMD]	= "PMA/PMD",
 	[LOOPBACK_XPORT]	= "XPORT",
 	[LOOPBACK_XGMII_WS]	= "XGMII_WS",
-	[LOOPBACK_XAUI_WS]  	= "XAUI_WS",
+	[LOOPBACK_XAUI_WS]	= "XAUI_WS",
 	[LOOPBACK_XAUI_WS_FAR]  = "XAUI_WS_FAR",
 	[LOOPBACK_XAUI_WS_NEAR] = "XAUI_WS_NEAR",
-	[LOOPBACK_GMII_WS] 	= "GMII_WS",
+	[LOOPBACK_GMII_WS]	= "GMII_WS",
 	[LOOPBACK_XFI_WS]	= "XFI_WS",
 	[LOOPBACK_XFI_WS_FAR]	= "XFI_WS_FAR",
-	[LOOPBACK_PHYXS_WS]  	= "PHYXS_WS",
+	[LOOPBACK_PHYXS_WS]	= "PHYXS_WS",
 };
 
 const unsigned int efx_reset_type_max = RESET_TYPE_MAX;