Red Hat: CVE-2025-37884: kernel: bpf: Fix deadlock between rcu_tasks_trace and event_mutex.

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

bpf: Fix deadlock between rcu_tasks_trace and event_mutex.

Fix the following deadlock:
CPU A
_free_event()
perf_kprobe_destroy()
mutex_lock(&event_mutex)
perf_trace_event_unreg()
synchronize_rcu_tasks_trace()

There are several paths where _free_event() grabs event_mutex
and calls sync_rcu_tasks_trace. Above is one such case.

CPU B
bpf_prog_test_run_syscall()
rcu_read_lock_trace()
bpf_prog_run_pin_on_cpu()
bpf_prog_load()
bpf_tracing_func_proto()
trace_set_clr_event()
mutex_lock(&event_mutex)

Delegate trace_set_clr_event() to workqueue to avoid
such lock dependency.