[Fix](bangc-ops): fix memory leak

[PetrelYy]

Thanks for your contribution and we appreciate it a lot.

1. Motivation

Feature: fix memory leak

2. Modification

[Please briefly describe what modification is made in this pull request, and indicate where to make the modification.](modified: ../test/mlu_op_gtest/pb_gtest/src/zoo/dynamic_point_to_voxel_forward/dynamic_point_to_voxel_forward.cpp)

3. Test Report

If you want to know how to do operator testing, you can see GTest-User-Guide-zh.

3.1 Modification Details

3.1.1 Accuracy Acceptance Standard

For static threshold standard details, see: MLU-OPS Accuracy Acceptance Standard.

• diff1: diff1 <= 3e-3
• diff2: diff2 <= 3e-3

3.1.2 Operator Scheme checklist

No.	Details	Check Results
1	Supported hardware	MLU370 MLU590
2	Job types	block U1 U4
3	Layouts	NHWC 、NCHW、ARRAY etc
4	Whether multi-dimensions are supported
5	Whether element zero is supported
6	Data type(half/float)	half / float etc
7	Whether there is size limit

3.1.3 New Feature Test

If you have checked the following items, please tick the relevant box.

• Data type test
• Multi-dimensional tensor test
• Layout test
• Different size/integer remainder end segment/alignment misalignment test
• Zero dimensional tensor test/zero element test
• stability test
• Multiple platform test
• Gen_case module test
• Nan/INF tests
• Bug fix tests
• For memory leak check details, seeGTest-User-Guide-zh.
• For code coverage check details, see: GTest-User-Guide-zh.
• For I/O calculation efficiency check details, see: MLU-OPS Performance Acceptance Standard.

3.1.4 Parameter Check

When a new operator is submitted, the test points are given and the test results are stated.

Test Point	Acceptance Standard	Test Result (Error Message)
Whether it conforms to the operator restriction	Normal error
Whether illegal parameters are passed	Normal error

3.2 Accuracy Test

For the cases used in the New Feature Test section, the features and the number of cases are recorded here. When multiple operations are tested, multiple tables are needed to include details of these operations.

Operation:

Test Point	Description	Quantity	Comment
Data type test	half/float/int8		pass
Mult-tensor test	Supports 1-8 dims		pass
Layout test	Supports NCHW/NHWC		none
Zero element test	Whether to support this test		none
Stability test	--gtest_repeat=NUM --thread=NUM		pass
mlu-only mode test	--mlu-only,see MLU-OPS Performance Acceptance Standard		none
Mult-platform test	MLU370/MLU590		pass
Nan/INF test	Whether to support this test		pass
Memory leak check	Test result		pass
Code coverage check	Test result		none