bpf: fix stack state printing in verifier log

fix incorrect stack state prints in print_verifier_state()

Fixes: 638f5b90 ("bpf: reduce verifier memory consumption")
Signed-off-by: NAlexei Starovoitov <ast@kernel.org>
Acked-by: NJohn Fastabend <john.fastabend@gmail.com>
Acked-by: NDaniel Borkmann <daniel@iogearbox.net>
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>

kernel/bpf/verifier.c

@@ -279,7 +279,7 @@ static void print_verifier_state(struct bpf_verifier_env *env,
 	for (i = 0; i < state->allocated_stack / BPF_REG_SIZE; i++) {
 		if (state->stack[i].slot_type[0] == STACK_SPILL)
 			verbose(env, " fp%d=%s",
-				-MAX_BPF_STACK + i * BPF_REG_SIZE,
+				(-i - 1) * BPF_REG_SIZE,
 				reg_type_str[state->stack[i].spilled_ptr.type]);
 	}
 	verbose(env, "\n");