cxgb: avoid open-coded offsetof()

clang-14 does not like the custom offsetof() macro in vsc7326:

drivers/net/ethernet/chelsio/cxgb/vsc7326.c:597:3: error: performing pointer subtraction with a null pointer has undefined behavior [-Werror,-Wnull-pointer-subtraction]
                HW_STAT(RxUnicast, RxUnicastFramesOK),
                ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
drivers/net/ethernet/chelsio/cxgb/vsc7326.c:594:56: note: expanded from macro 'HW_STAT'
        { reg, (&((struct cmac_statistics *)NULL)->stat_name) - (u64 *)NULL }

Rewrite this to use the version provided by the kernel.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/ethernet/chelsio/cxgb/vsc7326.c b/drivers/net/ethernet/chelsio/cxgb/vsc7326.c
index 873c1c7..a19284b 100644 (file)
--- a/drivers/net/ethernet/chelsio/cxgb/vsc7326.c
+++ b/drivers/net/ethernet/chelsio/cxgb/vsc7326.c
@@ -591,7 +591,7 @@ static void port_stats_update(struct cmac *mac)
        } hw_stats[] = {
 
 #define HW_STAT(reg, stat_name) \
-       { reg, (&((struct cmac_statistics *)NULL)->stat_name) - (u64 *)NULL }
+       { reg, offsetof(struct cmac_statistics, stat_name) / sizeof(u64) }
 
                /* Rx stats */
                HW_STAT(RxUnicast, RxUnicastFramesOK),