Misc fixes from PR 381 (#443)

* Remove Vendor constants from tracing plugins

Unused. And confusing, since "ot" may mean "opentracing" as well.

* Simplify current span key declaration

No need for a block.

* Fix typo

Co-authored-by: Joshua MacDonald <jmacd@users.noreply.github.com>

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)

plugin/grpctrace/grpctrace.go

@@ -24,11 +24,6 @@ import (
 	"go.opentelemetry.io/otel/api/trace"
 )
 
-const (
-	// Vendor is the integration provider
-	Vendor = "ot"
-)
-
 var (
 	propagator = trace.TraceContext{}
 )

plugin/httptrace/httptrace.go

@@ -23,10 +23,6 @@ import (
 	"go.opentelemetry.io/otel/api/trace"
 )
 
-const (
-	Vendor = "ot"
-)
-
 var (
 	HostKey = key.New("http.host")
 	URLKey  = key.New("http.url")

plugin/othttp/handler_example_test.go

@@ -76,7 +76,7 @@ func ExampleNewHandler() {
 			func(w http.ResponseWriter, r *http.Request) {
 				ctx := r.Context()
 				var name string
-				// Wrap another function in it's own span
+				// Wrap another function in its own span
 				if err := trace.SpanFromContext(ctx).Tracer().WithSpan(ctx, "figureOutName",
 					func(ctx context.Context) error {
 						var err error