internal/database: only log QueryRow debug info if error

QueryRow debug info is only logged now if there is an error. Logging on
every call resulted in too much noise.

For golang/go#39629

Change-Id: I5e5be0b1b4bdeda0ebe2618a7036fbf521c225a7
Reviewed-on: https://go-review.googlesource.com/c/pkgsite/+/262702
Trust: Julie Qiu <[email protected]>
Run-TryBot: Julie Qiu <[email protected]>
TryBot-Result: kokoro <[email protected]>
Reviewed-by: Jonathan Amsterdam <[email protected]>

Author: julieqiu

internal/database/database.go

@@ -114,8 +114,6 @@ func (db *DB) QueryRow(ctx context.Context, query string, args ...interface{}) *
 		msg := fmt.Sprintf("args=%v; elapsed=%q, start=%q, deadline=%q", args, time.Since(start), start, d)
 		if ctx.Err() != nil {
 			log.Errorf(ctx, "QueryRow context error: %v "+msg, ctx.Err())
-		} else {
-			log.Debugf(ctx, "QueryRow: "+msg)
 		}
 		logQuery(ctx, query, args, db.instanceID)(nil)
 	}()