New Mojom parser: Fix error message for invalid enum value initailizers.

mojom/mojom_parser/mojom/computed_data.go

Index: mojom/mojom_parser/mojom/computed_data.go
diff --git a/mojom/mojom_parser/mojom/computed_data.go b/mojom/mojom_parser/mojom/computed_data.go
index f5e6fe6bd160ea89b4971c6c81a0b7e5c1122103..9297df5547198fea6ca46de819f4c8a7b11ca7c1 100644
--- a/mojom/mojom_parser/mojom/computed_data.go
+++ b/mojom/mojom_parser/mojom/computed_data.go
@@ -95,7 +95,7 @@ func (d *MojomDescriptor) int32EnumValueFromValue(enum *MojomEnum, valueRef Valu
 			} else {
 				// TODO(rudominer) Allow enum values to be initialized to other enum values as long
 				// as the assignment chain is well-founded.
-				message := fmt.Sprintf("Error: The reference %s is being used as an enum value initializer but it has resolved to a "+
+				message := fmt.Sprintf("The reference %s is being used as an enum value initializer but it has resolved to a "+
 					"different enum value that itself does not yet have an integer value.", specifiedValue.identifier)
 				message = UserErrorMessage(specifiedValue.scope.file, specifiedValue.token, message)
 				return 0, fmt.Errorf(message)