internal/cgrouptest: use t.Cleanup instead of defer in InCgroupV2

Using defer may cause the TestCgroupGOMAXPROCS fail with the following
error messages,

--- FAIL: TestCgroupGOMAXPROCS (5.14s)
    crash_test.go:193: running /home/ms/src/go/bin/go build -o /tmp/go-build2154548206/testprog.exe
    crash_test.go:216: built testprog in 5.13507196s
    --- FAIL: TestCgroupGOMAXPROCS/containermaxprocs=0 (0.00s)
        cgroup_linux_test.go:60: /tmp/go-build2154548206/testprog.exe PrintGOMAXPROCS (1.191505ms): ok
        cgrouptest_linux.go:81: Error removing cgroup directory: remove /sys/fs/cgroup/user.slice/user-1000.slice/user@1000.service/go-cgrouptest4138918176: device or resource busy

Under the following environment,

- Linux 6.19.9-arch1-1 #1 SMP PREEMPT_DYNAMIC
- systemd 260 (260.1-1-arch)

Change-Id: Ic36b0b98f0d589ea5730ea35097af04a22dc7469

1 files changed, 3 insertions, 3 deletions

diff --git a/src/internal/cgrouptest/cgrouptest_linux.go b/src/internal/cgrouptest/cgrouptest_linux.go
index ad9599c938..72380debc6 100644
--- a/src/internal/cgrouptest/cgrouptest_linux.go
+++ b/src/internal/cgrouptest/cgrouptest_linux.go
@@ -74,16 +74,16 @@ func InCgroupV2(t *testing.T, fn func(*CgroupV2)) {
 	//
 	// TODO(prattmic): Consider running everything in a subprocess just so
 	// we can clean up if it throws or otherwise doesn't run the defers.
-	defer func() {
+	t.Cleanup(func() {
 		if err := os.Remove(path); err != nil {
 			// Not much we can do, but at least inform of the
 			// problem.
 			t.Errorf("Error removing cgroup directory: %v", err)
 		}
-	}()
+	})
 
 	migrateTo(t, path)
-	defer migrateTo(t, orig)
+	t.Cleanup(func() { migrateTo(t, orig) })
 
 	c := &CgroupV2{
 		orig: orig,