am65-cpsw: avoid null pointer arithmetic
clang warns about arithmetic on NULL pointers:
drivers/net/ethernet/ti/am65-cpsw-ethtool.c:71:2: error: performing pointer subtraction with a null pointer has undefined behavior [-Werror,-Wnull-pointer-subtraction]
AM65_CPSW_REGDUMP_REC(AM65_CPSW_REGDUMP_MOD_NUSS, 0x0, 0x1c),
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
drivers/net/ethernet/ti/am65-cpsw-ethtool.c:64:29: note: expanded from macro 'AM65_CPSW_REGDUMP_REC'
.hdr.len = (((u32 *)(end)) - ((u32 *)(start)) + 1) * sizeof(u32) * 2 + \
^ ~~~~~~~~~~~~~~~~
The expression here is easily changed to a calculation based on integers
that is no less readable.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: David S. Miller <davem@davemloft.net>