Correct spelling: decription -> description

Signed-off-by: Michael Vetter <jubalh@iodoru.org>

registry/api/errcode/errors.go

@@ -147,7 +147,7 @@ type ErrorDescriptor struct {
 	// keyed value when serializing api errors.
 	Value string
 
-	// Message is a short, human readable decription of the error condition
+	// Message is a short, human readable description of the error condition
 	// included in API responses.
 	Message string