bpf: Set run context for rawtp test_run callback

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

bpf: Set run context for rawtp test_run callback

syzbot reported crash when rawtp program executed through the

test_run interface calls bpf_get_attach_cookie helper or any

other helper that touches task->bpf_ctx pointer.

Setting the run context (task->bpf_ctx pointer) for test_run

callback.