samples/bpf: xdp_redirect_cpu have not need for read_trace_pipe

The sample xdp_redirect_cpu is not using helper bpf_trace_printk.
Thus it makes no sense that the --debug option us reading
from /sys/kernel/debug/tracing/trace_pipe via read_trace_pipe.
Simply remove it.
Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>

samples/bpf/xdp_redirect_cpu_user.c

@@ -51,7 +51,6 @@ static const struct option long_options[] = {
 	{"help",	no_argument,		NULL, 'h' },
 	{"dev",		required_argument,	NULL, 'd' },
 	{"skb-mode",	no_argument,		NULL, 'S' },
-	{"debug",	no_argument,		NULL, 'D' },
 	{"sec",		required_argument,	NULL, 's' },
 	{"prognum",	required_argument,	NULL, 'p' },
 	{"qsize",	required_argument,	NULL, 'q' },
@@ -563,7 +562,6 @@ int main(int argc, char **argv)
 	bool use_separators = true;
 	bool stress_mode = false;
 	char filename[256];
-	bool debug = false;
 	int added_cpus = 0;
 	int longindex = 0;
 	int interval = 2;
@@ -624,9 +622,6 @@ int main(int argc, char **argv)
 		case 'S':
 			xdp_flags |= XDP_FLAGS_SKB_MODE;
 			break;
-		case 'D':
-			debug = true;
-			break;
 		case 'x':
 			stress_mode = true;
 			break;
@@ -688,11 +683,6 @@ int main(int argc, char **argv)
 		return EXIT_FAIL_XDP;
 	}
 
-	if (debug) {
-		printf("Debug-mode reading trace pipe (fix #define DEBUG)\n");
-		read_trace_pipe();
-	}
-
 	stats_poll(interval, use_separators, prog_num, stress_mode);
 	return EXIT_OK;
 }