tipc: fix a missing check of genlmsg_put

genlmsg_put could fail. The fix inserts a check of its return value, and
if it fails, returns -EMSGSIZE.
Signed-off-by: Kangjie Lu <kjlu@umn.edu>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/tipc/netlink_compat.c

@@ -904,6 +904,8 @@ static int tipc_nl_compat_publ_dump(struct tipc_nl_compat_msg *msg, u32 sock)
 
 	hdr = genlmsg_put(args, 0, 0, &tipc_genl_family, NLM_F_MULTI,
 			  TIPC_NL_PUBL_GET);
+	if (!hdr)
+		return -EMSGSIZE;
 
 	nest = nla_nest_start(args, TIPC_NLA_SOCK);
 	if (!nest) {