CVE-2023-54197

In the Linux kernel, the following vulnerability has been resolved:

Revert "Bluetooth: btsdio: fix use after free bug in btsdio_remove due to unfinished work"

This reverts commit 1e9ac114c4428fdb7ff4635b45d4f46017e8916f.

This patch introduces a possible null-ptr-def problem. Revert it. And the
fixed bug by this patch have resolved by commit 73f7b171b7c0 ("Bluetooth:
btsdio: fix use after free bug in btsdio_remove due to race condition").