[tools/syscount.py]: fix total_ns wrong count
It's useful to know each syscall's total latency
in that period, but not the latency of the last time
in that period.
@@ -481,7 +481,7 @@ TRACEPOINT_PROBE(raw_syscalls, sys_exit) {
val = data.lookup_or_init(&key, &zero);
val->count++;
- val->total_ns = bpf_ktime_get_ns() - *start_ns;
+ val->total_ns += bpf_ktime_get_ns() - *start_ns;
#else
u64 *val, zero = 0;
val = data.lookup_or_init(&key, &zero);
