all: gofmt

Gofmt to update doc comments to the new formatting.

For golang/go#51082.

Change-Id: I9a1c4b671c06820a1c383ee515f7884965fefa54
Reviewed-on: https://go-review.googlesource.com/c/sys/+/399602
Reviewed-by: Ian Lance Taylor <iant@google.com>
Auto-Submit: Russ Cox <rsc@golang.org>
TryBot-Result: Gopher Robot <gobot@golang.org>
Run-TryBot: Russ Cox <rsc@golang.org>

plan9/syscall.go

@@ -113,5 +113,6 @@ func (tv *Timeval) Nano() int64 {
 
 // use is a no-op, but the compiler cannot see that it is.
 // Calling use(p) ensures that p is kept live until that point.
+//
 //go:noescape
 func use(p unsafe.Pointer)