mctp: Be explicit about struct sockaddr_mctp padding

We currently have some implicit padding in struct sockaddr_mctp. This
patch makes this padding explicit, and ensures we have consistent
layout on platforms with <32bit alignmnent.

Fixes: 60fc6398 ("mctp: Add sockaddr_mctp to uapi")
Signed-off-by: NJeremy Kerr <jk@codeconstruct.com.au>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

include/uapi/linux/mctp.h

@@ -20,10 +20,12 @@ struct mctp_addr {
 
 struct sockaddr_mctp {
 	__kernel_sa_family_t	smctp_family;
+	__u16			__smctp_pad0;
 	unsigned int		smctp_network;
 	struct mctp_addr	smctp_addr;
 	__u8			smctp_type;
 	__u8			smctp_tag;
+	__u8			__smctp_pad1;
 };
 
 #define MCTP_NET_ANY		0x0