runtime/race: fix comment in select_test.TestNoRaceSelect1

selectGoImpl was merged into selectGo in https://golang.org/cl/37860.

Change-Id: I39985f37223743f1ea0aba9bee0e2708398a925c
GitHub-Last-Rev: ec97b4b
GitHub-Pull-Request: #38716
Reviewed-on: https://go-review.googlesource.com/c/go/+/230340
Reviewed-by: Ian Lance Taylor <iant@golang.org>

Author: cncal

Diff for: src/runtime/race/testdata/select_test.go

@@ -20,7 +20,7 @@ func TestNoRaceSelect1(t *testing.T) {
 		x = 1
 		// At least two channels are needed because
 		// otherwise the compiler optimizes select out.
-		// See comment in runtime/select.go:^func selectgoImpl.
+		// See comment in runtime/select.go:^func selectgo.
 		select {
 		case c <- true:
 		case c1 <- true: