nettrace: place min-latency togather with filter condition

Signed-off-by: Menglong Dong <imagedong@tencent.com>

Author: menglongdong

src/nettrace.c

@@ -41,10 +41,17 @@ static void do_parse_args(int argc, char *argv[])
 			.dest = &bpf_args->pid, .set = &bpf_args->enable_pid,
 			.desc = "filter by current process id(pid)",
 		},
+		{
+			.lname = "min-latency", .dest = &trace_args->min_latency,
+			.type = OPTION_U32,
+			.desc = "filter by the minial time to live of the skb in ms",
+		},
+		{ .type = OPTION_BLANK },
 		{
 			.lname = "trace", .sname = 't',
 			.dest = &trace_args->traces,
-			.desc = "enable trace group or trace",
+			.desc = "enable trace group or trace. Some traces are "
+				"disabled by default, use \"all\" to enable all",
 		},
 		{
 			.lname = "force", .dest = &trace_args->force,
@@ -103,11 +110,6 @@ static void do_parse_args(int argc, char *argv[])
 			.desc = "print the kernel function call stack of kfree_skb",
 		},
 #endif
-		{
-			.lname = "min-latency", .dest = &trace_args->min_latency,
-			.type = OPTION_U32,
-			.desc = "the minial time to live of the skb in ms",
-		},
 		{
 			.lname = "sock", .dest = &trace_args->sock,
 			.type = OPTION_BOOL,