CVE-2024-40909 bpf: Fix a potential use-after-free in bpf_link_free()

In the Linux kernel, the following vulnerability has been resolved: bpf: Fix a potential use-after-free in bpflinkfree After commit 1a80dbcb2dba, bpflink can be freed by link-ops-deallocdeferred, but the code still tests and uses link-ops-dealloc afterward, which leads to a use-after-free as...