[PATCH net] r8169: give RTL_GIGA_MAC_VER_EXTENDED a distinct value

[Karl Mehltretter <kmehltretter@gmail.com>]

RTL_GIGA_MAC_VER_EXTENDED implicitly follows
RTL_GIGA_MAC_VER_LAST = RTL_GIGA_MAC_NONE - 1, so it has the same value
as RTL_GIGA_MAC_NONE.

rtl_init_one() therefore sends unknown chips through extended detection.
If TX_CONFIG_V2 reads as zero, they are misidentified as RTL9151AS
instead of being rejected.

Give RTL_GIGA_MAC_VER_EXTENDED a distinct value. It is only a detection
marker and is never stored in tp->mac_version.

Found by Clang's -Wduplicate-enum and verified with a QEMU stub.

Fixes: 5e3c5a2b85da9 ("r8169: add support for extended chip version id and RTL9151AS")
Cc: stable@vger.kernel.org
Assisted-by: Claude:claude-fable-5
Signed-off-by: Karl Mehltretter <kmehltretter@gmail.com>
---
 drivers/net/ethernet/realtek/r8169.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/realtek/r8169.h b/drivers/net/ethernet/realtek/r8169.h
index 0b9c1d4eb48ba..fb772cc043105 100644
--- a/drivers/net/ethernet/realtek/r8169.h
+++ b/drivers/net/ethernet/realtek/r8169.h
@@ -74,7 +74,7 @@ enum mac_version {
 	RTL_GIGA_MAC_VER_80,
 	RTL_GIGA_MAC_NONE,
 	RTL_GIGA_MAC_VER_LAST = RTL_GIGA_MAC_NONE - 1,
-	RTL_GIGA_MAC_VER_EXTENDED
+	RTL_GIGA_MAC_VER_EXTENDED = RTL_GIGA_MAC_NONE + 1
 };
 
 struct rtl8169_private;
-- 
2.53.0