*: Obey current Go suggested rule to format lists in comments

Until https://github.com/golang/go/issues/7873 is fixed/implemented,
let's follow the currently advised scheme to indent lists and this way
put them as pre-formatted text.

We already do so mostly everywhere, but 2 of the places were not
following it and thus all items there were rendered as one line.

tracing/tracing.go

@@ -137,14 +137,14 @@ For testing purposes it is sometimes practical to leverage the property that
 probes pause original code execution until the probe run is finished. That
 means while the probe is running original goroutine
 
-- is paused at well-defined point (where trace function is called), thus
-- it cannot mutate any state it is programmed to mutate.
+	- is paused at well-defined point (where trace function is called), thus
+	- it cannot mutate any state it is programmed to mutate.
 
 Using this properties it is possible to attach testing probes and verify that
 a set of goroutines in tested code in question
 
-- produce events in correct order, and
-- at every event associated internal state is correct.
+	- produce events in correct order, and
+	- at every event associated internal state is correct.
 
 TODO example.