Fix fd leak of shim log

Open shim v2 log with the flag `O_RDWR` will cause the `Read()` block
forever even if the pipe has been closed on the shim side. Then the
`io.Copy()` would never return and lead to a fd leak.
Fix typo when closing shim v1 log which causes the `stdouLog` leak.
Update `numPipes` function in test case to get the opened FIFO
correctly.

Signed-off-by: Li Yuxuan <liyuxuan04@baidu.com>

container_linux_test.go

@@ -330,7 +330,7 @@ func TestShimDoesNotLeakPipes(t *testing.T) {
 }
 
 func numPipes(pid int) (int, error) {
-	cmd := exec.Command("sh", "-c", fmt.Sprintf("lsof -p %d | grep pipe", pid))
+	cmd := exec.Command("sh", "-c", fmt.Sprintf("lsof -p %d | grep FIFO", pid))
 
 	var stdout bytes.Buffer
 	cmd.Stdout = &stdout