Revert "UAPI: ethtool: Use __struct_group() in struct ethtool_link_settings"

This reverts commit 43d3487. We cannot
use tagged struct groups in UAPI because C++ will throw syntax errors
even under "extern C".

Signed-off-by: Kees Cook <kees@kernel.org>
Link: https://patch.msgid.link/20241115204308.3821419-2-kees@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Author: kees

include/uapi/linux/ethtool.h

@@ -2511,24 +2511,21 @@ enum ethtool_reset_flags {
  *	autonegotiation; 0 if unknown or not applicable.  Read-only.
  */
 struct ethtool_link_settings {
-	/* New members MUST be added within the __struct_group() macro below. */
-	__struct_group(ethtool_link_settings_hdr, hdr, /* no attrs */,
-		__u32	cmd;
-		__u32	speed;
-		__u8	duplex;
-		__u8	port;
-		__u8	phy_address;
-		__u8	autoneg;
-		__u8	mdio_support;
-		__u8	eth_tp_mdix;
-		__u8	eth_tp_mdix_ctrl;
-		__s8	link_mode_masks_nwords;
-		__u8	transceiver;
-		__u8	master_slave_cfg;
-		__u8	master_slave_state;
-		__u8	rate_matching;
-		__u32	reserved[7];
-	);
+	__u32	cmd;
+	__u32	speed;
+	__u8	duplex;
+	__u8	port;
+	__u8	phy_address;
+	__u8	autoneg;
+	__u8	mdio_support;
+	__u8	eth_tp_mdix;
+	__u8	eth_tp_mdix_ctrl;
+	__s8	link_mode_masks_nwords;
+	__u8	transceiver;
+	__u8	master_slave_cfg;
+	__u8	master_slave_state;
+	__u8	rate_matching;
+	__u32	reserved[7];
 	__u32	link_mode_masks[];
 	/* layout of link_mode_masks fields:
 	 * __u32 map_supported[link_mode_masks_nwords];