In the previous code, there was a memory leak issue where the previously allocated memory was not freed upon a failed realloc operation. This commit addresses the problem by releasing the old memory before setting the pointer to NULL in case of a realloc failure. This ensures that memory is properly managed and avoids potential memory leaks.

Pull Request Readiness Checklist

See details at https://github.com/opencv/opencv/wiki/How_to_contribute#making-a-good-pull-request

• I agree to contribute to the project under Apache 2 License.
• To the best of my knowledge, the proposed patch is not based on a code under GPL or another license that is incompatible with OpenCV
• The PR is proposed to the proper branch
• There is a reference to the original bug report and related work
• There is accuracy test, performance test and test data in opencv_extra repository, if applicable
  Patch to opencv_extra has the same branch name.