pool: Fix NPE in AIO test

Payload reader is nil when error. Also replace `defer` with native test
cleaner.

Signed-off-by: Leonard Lyubich <leonard@morphbits.io>

pool/pool_aio_test.go

@@ -341,11 +341,9 @@ func testPoolInterfaceWithAIO(t *testing.T, nodeAddr string) {
 		var cmd client.PrmObjectGet
 
 		hdr, read, err := pool.ObjectGetInit(ctxTimeout, containerID, objectID, signer, cmd)
-		defer func() {
-			_ = read.Close()
-		}()
-
 		require.NoError(t, err)
+		t.Cleanup(func() { _ = read.Close() })
+
 		require.False(t, hdr.Owner().IsZero())
 		require.True(t, hdr.Owner() == account)
 
@@ -498,11 +496,9 @@ func testPoolWaiterWithAIO(t *testing.T, nodeAddr string) {
 		var cmd client.PrmObjectGet
 
 		hdr, read, err := pool.ObjectGetInit(ctxTimeout, containerID, objectID, signer, cmd)
-		defer func() {
-			_ = read.Close()
-		}()
-
 		require.NoError(t, err)
+		t.Cleanup(func() { _ = read.Close() })
+
 		require.False(t, hdr.Owner().IsZero())
 		require.True(t, hdr.Owner() == account)
 
@@ -654,11 +650,9 @@ func testClientWaiterWithAIO(t *testing.T, nodeAddr string) {
 		var cmd client.PrmObjectGet
 
 		hdr, read, err := cl.ObjectGetInit(ctxTimeout, containerID, objectID, signer, cmd)
-		defer func() {
-			_ = read.Close()
-		}()
-
 		require.NoError(t, err)
+		t.Cleanup(func() { _ = read.Close() })
+
 		require.False(t, hdr.Owner().IsZero())
 		require.True(t, hdr.Owner() == account)