cri: fix integration test on cgroupsv2 system

TestUpdateContainerResources_MemoryLimit still uses old method to
check memlimit in cgroup.

Signed-off-by: Shengjing Zhu <zhsj@debian.org>
(cherry picked from commit 775facd)
Signed-off-by: Wei Fu <fuweid89@gmail.com>

integration/container_update_resources_test.go

@@ -270,11 +270,8 @@ func TestUpdateContainerResources_MemoryLimit(t *testing.T) {
 	require.NoError(t, err)
 
 	t.Log("Check memory limit in cgroup")
-	cgroup, err := cgroups.Load(cgroups.V1, cgroups.PidPath(int(task.Pid())))
-	require.NoError(t, err)
-	stat, err := cgroup.Stat(cgroups.IgnoreNotExist)
-	require.NoError(t, err)
-	assert.Equal(t, uint64(400*1024*1024), stat.Memory.Usage.Limit)
+	memLimit := getCgroupMemoryLimitForTask(t, task)
+	assert.Equal(t, uint64(400*1024*1024), memLimit)
 	swapLimit := getCgroupSwapLimitForTask(t, task)
 	assert.Equal(t, uint64(400*1024*1024), swapLimit)
 
@@ -291,9 +288,8 @@ func TestUpdateContainerResources_MemoryLimit(t *testing.T) {
 	checkMemorySwapLimit(t, spec, expectedSwapLimit(800*1024*1024))
 
 	t.Log("Check memory limit in cgroup")
-	stat, err = cgroup.Stat(cgroups.IgnoreNotExist)
-	require.NoError(t, err)
-	assert.Equal(t, uint64(800*1024*1024), stat.Memory.Usage.Limit)
+	memLimit = getCgroupMemoryLimitForTask(t, task)
+	assert.Equal(t, uint64(800*1024*1024), memLimit)
 	swapLimit = getCgroupSwapLimitForTask(t, task)
 	assert.Equal(t, uint64(800*1024*1024), swapLimit)
 }