cmd/compile: remove unnecessary fmt.Sprintf call

Change-Id: I38ba7cb0179ec9226a68629c53ea2d81fa19c059
GitHub-Last-Rev: a3d4fe2
GitHub-Pull-Request: #66024
Reviewed-on: https://go-review.googlesource.com/c/go/+/568115
Auto-Submit: Ian Lance Taylor <iant@google.com>
Reviewed-by: Robert Griesemer <gri@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Ian Lance Taylor <iant@google.com>
Commit-Queue: Ian Lance Taylor <iant@google.com>
Reviewed-by: qiulaidongfeng <2645477756@qq.com>
Auto-Submit: Robert Griesemer <gri@google.com>

src/cmd/compile/internal/base/hashdebug.go

@@ -197,7 +197,7 @@ func NewHashDebug(ev, s string, file io.Writer) *HashDebug {
 			break
 		}
 		if i == 0 {
-			hd.matches = append(hd.matches, toHashAndMask(s, fmt.Sprintf("%s", ev)))
+			hd.matches = append(hd.matches, toHashAndMask(s, ev))
 		} else {
 			hd.matches = append(hd.matches, toHashAndMask(s, fmt.Sprintf("%s%d", ev, i-1)))
 		}