if_link: add IFLA_TARGET_NETNSID alias

This adds IFLA_TARGET_NETNSID as an alias for IFLA_IF_NETNSID for
RTM_*LINK requests.
The new name is clearer and also aligns with the newly introduced
IFA_TARGET_NETNSID propert for RTM_*ADDR requests.

Signed-off-by: Christian Brauner <christian@brauner.io>
Suggested-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Cc: Jiri Benc <jbenc@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

include/uapi/linux/if_link.h

@@ -161,6 +161,7 @@ enum {
 	IFLA_EVENT,
 	IFLA_NEW_NETNSID,
 	IFLA_IF_NETNSID,
+	IFLA_TARGET_NETNSID = IFLA_IF_NETNSID, /* new alias */
 	IFLA_CARRIER_UP_COUNT,
 	IFLA_CARRIER_DOWN_COUNT,
 	IFLA_NEW_IFINDEX,

tools/include/uapi/linux/if_link.h

@@ -161,6 +161,7 @@ enum {
 	IFLA_EVENT,
 	IFLA_NEW_NETNSID,
 	IFLA_IF_NETNSID,
+	IFLA_TARGET_NETNSID = IFLA_IF_NETNSID, /* new alias */
 	IFLA_CARRIER_UP_COUNT,
 	IFLA_CARRIER_DOWN_COUNT,
 	IFLA_NEW_IFINDEX,