doc: adjust bpf_ktime_get_ns() document description
@@ -481,7 +481,7 @@ Examples in situ:
Syntax: ```u64 bpf_ktime_get_ns(void)```
-Return: current time in nanoseconds
+Return: u64 number of nanoseconds. Starts at system boot time but stops during suspend.
Examples in situ:
[search /examples](https://github.com/iovisor/bcc/search?q=bpf_ktime_get_ns+path%3Aexamples&type=Code),
