selftests/net: optmem_max became per netns

/proc/sys/net/core/optmem_max is now per netns, change two tests
that were saving/changing/restoring its value on the parent netns.

cos-patch: bug
Change-Id: Idacd74a41133cbb849cca0d608a02dcad97da92b
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
(cherry picked from commit 18872ba8cd2406ffa835f9f6276e47ed86fbb5d6)
Reviewed-on: https://cos-review.googlesource.com/c/third_party/kernel/+/62584
Tested-by: Mina Almasry <almasrymina@google.com>
(cherry picked from commit 128a8bec61acef84adf608afa8590c0a81692796)
Reviewed-on: https://cos-review.googlesource.com/c/third_party/kernel/+/62741
Reviewed-by: Oleksandr Tymoshenko <ovt@google.com>
Main-Branch-Verified: Cusky Presubmit Bot <presubmit@cos-infra-prod.iam.gserviceaccount.com>
Reviewed-by: Neal Cardwell <ncardwell@google.com>
Tested-by: Cusky Presubmit Bot <presubmit@cos-infra-prod.iam.gserviceaccount.com>

tools/testing/selftests/net/msg_zerocopy.sh

diff --git a/tools/testing/selftests/net/msg_zerocopy.sh b/tools/testing/selftests/net/msg_zerocopy.sh
index 825ffec..89c22f5 100755
--- a/tools/testing/selftests/net/msg_zerocopy.sh
+++ b/tools/testing/selftests/net/msg_zerocopy.sh
@@ -70,23 +70,22 @@
 esac
 
 # Start of state changes: install cleanup handler
-save_sysctl_mem="$(sysctl -n ${path_sysctl_mem})"
 
 cleanup() {
 	ip netns del "${NS2}"
 	ip netns del "${NS1}"
-	sysctl -w -q "${path_sysctl_mem}=${save_sysctl_mem}"
 }
 
 trap cleanup EXIT
 
-# Configure system settings
-sysctl -w -q "${path_sysctl_mem}=1000000"
-
 # Create virtual ethernet pair between network namespaces
 ip netns add "${NS1}"
 ip netns add "${NS2}"
 
+# Configure system settings
+ip netns exec "${NS1}" sysctl -w -q "${path_sysctl_mem}=1000000"
+ip netns exec "${NS2}" sysctl -w -q "${path_sysctl_mem}=1000000"
+
 ip link add "${DEV}" mtu "${DEV_MTU}" netns "${NS1}" type veth \
   peer name "${DEV}" mtu "${DEV_MTU}" netns "${NS2}"