selftests: bonding: create directly devices in the target namespaces

If failed to set link1_1 to netns client, we should delete link1_1 in the
cleanup path. But if set link1_1 to netns client successfully, delete
link1_1 will report warning. So it will be safer creating directly the
devices in the target namespaces.
Reported-by: Hangbin Liu <liuhangbin@gmail.com>
Closes: https://lore.kernel.org/all/ZNyJx1HtXaUzOkNA@Laptop-X1/Signed-off-by: Zhengchao Shao <shaozhengchao@huawei.com>
Acked-by: Hangbin Liu <liuhangbin@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

tools/testing/selftests/drivers/net/bonding/bond-arp-interval-causes-panic.sh

@@ -22,14 +22,12 @@ server_ip4=192.168.1.254
 echo 180 >/proc/sys/kernel/panic
 
 # build namespaces
-ip link add dev link1_1 type veth peer name link1_2
-
 ip netns add "server"
-ip link set dev link1_2 netns server up name eth0
+ip netns add "client"
+ip -n client link add eth0 type veth peer name eth0 netns server
+ip netns exec server ip link set dev eth0 up
 ip netns exec server ip addr add ${server_ip4}/24 dev eth0
 
-ip netns add "client"
-ip link set dev link1_1 netns client down name eth0
 ip netns exec client ip link add dev bond0 down type bond mode 1 \
 	miimon 100 all_slaves_active 1
 ip netns exec client ip link set dev eth0 down master bond0