Fix OperatorError.

This used to work with Go 1.1, but only because of a compiler bug.
The bug is fixed in Go 1.2, so we have to fix our code now.

Change-Id: I5a9f3a15878afd750e848be33e90b05f3aa055e1

storage/interface.go

@@ -50,7 +50,7 @@ func (f FilterResult) String() string {
 type OperatorErrorType int
 
 type OperatorError struct {
-	error
+	Error       error
 	Continuable bool
 }
 

storage/metric/curator.go

@@ -369,7 +369,7 @@ func (w *watermarkScanner) Operate(key, _ interface{}) (oErr *storage.OperatorEr
 		// there was a decoding error with the entity and shouldn't be cause to stop
 		// work.  The process will simply start from a pessimistic work time and
 		// work forward.  With an idempotent processor, this is safe.
-		return &storage.OperatorError{error: err, Continuable: true}
+		return &storage.OperatorError{Error: err, Continuable: true}
 	}
 
 	keySet, _ := w.sampleKeys.Get()
@@ -400,13 +400,13 @@ func (w *watermarkScanner) Operate(key, _ interface{}) (oErr *storage.OperatorEr
 	if seeker.err != nil {
 		glog.Warningf("Got error in state machine: %s", seeker.err)
 
-		return &storage.OperatorError{error: seeker.err, Continuable: !seeker.iteratorInvalid}
+		return &storage.OperatorError{Error: seeker.err, Continuable: !seeker.iteratorInvalid}
 	}
 
 	if seeker.iteratorInvalid {
 		glog.Warningf("Got illegal iterator in state machine: %s", err)
 
-		return &storage.OperatorError{error: errIllegalIterator, Continuable: false}
+		return &storage.OperatorError{Error: errIllegalIterator, Continuable: false}
 	}
 
 	if !seeker.seriesOperable {
@@ -417,7 +417,7 @@ func (w *watermarkScanner) Operate(key, _ interface{}) (oErr *storage.OperatorEr
 	if err != nil {
 		// We can't divine the severity of a processor error without refactoring the
 		// interface.
-		return &storage.OperatorError{error: err, Continuable: false}
+		return &storage.OperatorError{Error: err, Continuable: false}
 	}
 
 	if err = w.curationState.Update(&curationKey{
@@ -429,7 +429,7 @@ func (w *watermarkScanner) Operate(key, _ interface{}) (oErr *storage.OperatorEr
 		// Under the assumption that the processors are idempotent, they can be
 		// re-run; thusly, the commitment of the curation remark is no cause
 		// to cease further progress.
-		return &storage.OperatorError{error: err, Continuable: true}
+		return &storage.OperatorError{Error: err, Continuable: true}
 	}
 
 	return nil

tools/dumper/main.go

@@ -60,7 +60,7 @@ func (d *SamplesDumper) Operate(key, value interface{}) *storage.OperatorError {
 		})
 		if err := d.Error(); err != nil {
 			return &storage.OperatorError{
-				error:       err,
+				Error:       err,
 				Continuable: false,
 			}
 		}