internal/lsp/cmd: replace time.Tick with time.After

time.Tick produces multiple ticks (and leaks a Ticker); time.After
produces a single tick, which is what is called for here.

Change-Id: I922b11e1263a8367afec76c10831b7284f3559ec
Reviewed-on: https://go-review.googlesource.com/c/tools/+/184938
Reviewed-by: Rebecca Stambler <rstambler@golang.org>
Reviewed-by: Ian Cottrell <iancottrell@google.com>
Run-TryBot: Rebecca Stambler <rstambler@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
diff --git a/internal/lsp/cmd/check.go b/internal/lsp/cmd/check.go
index c5d9960..0aa07fa 100644
--- a/internal/lsp/cmd/check.go
+++ b/internal/lsp/cmd/check.go
@@ -59,7 +59,7 @@
 	for _, file := range checking {
 		select {
 		case <-file.hasDiagnostics:
-		case <-time.Tick(30 * time.Second):
+		case <-time.After(30 * time.Second):
 			return fmt.Errorf("timed out waiting for results from %v", file.uri)
 		}
 		file.diagnosticsMu.Lock()