os, syscall: fix Plan 9 build
R=rsc
CC=golang-dev
https://golang.org/cl/5330067
diff --git a/src/pkg/syscall/syscall_plan9.go b/src/pkg/syscall/syscall_plan9.go
index 16f8e733..0cc8ee95 100644
--- a/src/pkg/syscall/syscall_plan9.go
+++ b/src/pkg/syscall/syscall_plan9.go
@@ -19,13 +19,13 @@
// An Error can represent any printable error condition.
type Error interface {
- String() string
+ error
}
// ErrorString implements Error's String method by returning itself.
type ErrorString string
-func (e ErrorString) String() string { return string(e) }
+func (e ErrorString) Error() string { return string(e) }
// NewError converts s to an ErrorString, which satisfies the Error interface.
func NewError(s string) Error { return ErrorString(s) }
