BLE: fix pointer not set to null on delete

[paul-szczepanek-arm]

Summary of changes

Fix missing setting of pointer to NULL on delete.

Impact of changes

Migration actions required

Documentation

Based on @AGlass0fMilk PR #12145, superseding it.

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Pull request type

[x] Patch update (Bug fix / Target update / Docs update / Test update / Refactor)
[] Feature update (New feature / Functionality change / New API)
[] Major update (Breaking change E.g. Return code change / API behaviour change)

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Test results

[] No Tests required for this change (E.g docs only update)
[x] Covered by existing mbed-os tests (Greentea or Unittest)
[] Tests / results supplied as part of this PR

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Reviewers

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[0xc0170]

@AGlass0fMilk Should we close #12145 ? Please review

[ciarmcom]

@paul-szczepanek-arm, thank you for your changes.
@ARMmbed/mbed-os-pan @ARMmbed/mbed-os-maintainers please review.

[AGlass0fMilk]

@0xc0170 @paul-szczepanek-arm

Were there still tabs in my original PR? 🤣

This seems to be missing the removal of the "double delete" that could occur upon SM reset:

https://github.com/ARMmbed/mbed-os/pull/12145/files#diff-080d4438cb8d004ac2bd9fca2be4f45bL833-L840

Now it'll just be trying to delete a NULL pointer.

[paul-szczepanek-arm]

checking a pointer for NULL is redundant in application code, the check is already performed inside delete

[0xc0170]

CI started

[mbed-ci]

Test run: SUCCESS

Summary: 11 of 11 test jobs passed
Build number : 1
Build artifacts

[0xc0170]

checking a pointer for NULL is redundant in application code, the check is already performed inside delete

@AGlass0fMilk This is ready for integration. All good here?

[AGlass0fMilk]

If that’s the case it should be all set.