From: "Dmitry V. Levin" <redacted>
Date: Tue, 28 Feb 2017 04:39:30 +0300

Replace MAX_ADDR_LEN with its numeric value to fix the following
linux/packet_diag.h userspace compilation error:

/usr/include/linux/packet_diag.h:67:17: error: 'MAX_ADDR_LEN' undeclared here (not in a function)
  __u8 pdmc_addr[MAX_ADDR_LEN];

This is not the first case in the UAPI where the numeric value
of MAX_ADDR_LEN is used, uapi/linux/if_link.h already does the same,
and there are no UAPI headers besides these two that use MAX_ADDR_LEN.

The alternative fix would be to include <linux/netdevice.h> which
pulls in other headers and a lot of definitions with them.

Signed-off-by: Dmitry V. Levin <redacted>

If if_link.h includes netdevice.h properly, let's try to do the same here as well.

Thanks.