net-sysfs: remove unused fmt_long_hex

Ever since commit 04ed3e74
("net: change netdev->features to u32") the format string
fmt_long_hex has not been used, so we may as well remove it.
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/core/net-sysfs.c

@@ -29,7 +29,6 @@
 
 #ifdef CONFIG_SYSFS
 static const char fmt_hex[] = "%#x\n";
-static const char fmt_long_hex[] = "%#lx\n";
 static const char fmt_dec[] = "%d\n";
 static const char fmt_ulong[] = "%lu\n";
 static const char fmt_u64[] = "%llu\n";