bpf: Correct the comment about insn_to_jit_off

The insn_to_jit_off passed to bpf_prog_fill_jited_linfo should be the
first byte of the next instruction, or the byte off to the end of the
current instruction.
Signed-off-by: NPu Lehui <pulehui@huawei.com>
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>
Signed-off-by: NAndrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20220530092815.1112406-4-pulehui@huawei.com

kernel/bpf/core.c

@@ -176,7 +176,7 @@ void bpf_prog_jit_attempt_done(struct bpf_prog *prog)
  * here is relative to the prog itself instead of the main prog.
  * This array has one entry for each xlated bpf insn.
  *
- * jited_off is the byte off to the last byte of the jited insn.
+ * jited_off is the byte off to the end of the jited insn.
  *
  * Hence, with
  * insn_start: