lsm-nice-ebpf: is the deny condition for renice correctly implemented?

[p-alik]

An attempt to reproduce renice with negative value for LSM example failed.
The first part of the condition is false

book/examples/lsm-nice/lsm-nice-ebpf/src/main.rs

Line 41 in 4aa9a5b

if (*p).pid == core::ptr::read_volatile(&PID) && nice < 0 {

because of

book/examples/lsm-nice/lsm-nice-ebpf/src/main.rs

Line 18 in 4aa9a5b

static PID: i32 = 0;