Simplify current span key declaration

jmacd · krnowak · commit ae0f7d3f1223 · 2020-01-24T20:56:28.000+01:00
No need for a block.
diff --git a/api/trace/current.go b/api/trace/current.go
@@ -20,9 +20,7 @@ import (
 
 type currentSpanKeyType struct{}
 
-var (
-	currentSpanKey = &currentSpanKeyType{}
-)
+var currentSpanKey = &currentSpanKeyType{}
 
 func ContextWithSpan(ctx context.Context, span Span) context.Context {
 	return context.WithValue(ctx, currentSpanKey, span)
