internal/trace: fix Sync.ClockSnapshot comment

The old comment said "clocks take in close in time" which was probably
due to rewording this a few times.

Replace the comment with the one of the ClockSnapshot type as there
doesn't seem to be a good reason for using a different wording here.

Change-Id: I6a6a69648c8470c2f45f6f8e728f5dc8b121a82b
Reviewed-on: https://go-review.googlesource.com/c/go/+/694620
Reviewed-by: Michael Knyszek <[email protected]>
LUCI-TryBot-Result: Go LUCI <[email protected]>
Reviewed-by: David Chase <[email protected]>
Auto-Submit: Michael Knyszek <[email protected]>

Author: felixge

src/internal/trace/event.go

@@ -690,9 +690,11 @@ type Sync struct {
 	// N indicates that this is the Nth sync event in the trace.
 	N int
 
-	// ClockSnapshot is a snapshot of different clocks taken in close in time
-	// that can be used to correlate trace events with data captured by other
-	// tools. May be nil for older trace versions.
+	// ClockSnapshot represents a near-simultaneous clock reading of several
+	// different system clocks. The snapshot can be used as a reference to
+	// convert timestamps to different clocks, which is helpful for correlating
+	// timestamps with data captured by other tools. The value is nil for traces
+	// before go1.25.
 	ClockSnapshot *ClockSnapshot
 
 	// ExperimentalBatches contain all the unparsed batches of data for a given experiment.