Convert errors tracer into a separate package (#5221)

cmd/object-api-common_test.go

@@ -19,6 +19,8 @@ package cmd
 import (
 	"sync"
 	"testing"
+
+	"github.com/minio/minio/pkg/errors"
 )
 
 func TestHouseKeeping(t *testing.T) {
@@ -90,7 +92,7 @@ func TestHouseKeeping(t *testing.T) {
 		{nilDiskStorage, nil},
 	}
 	for i, test := range testCases {
-		actualErr := errorCause(houseKeeping(test.store))
+		actualErr := errors.Cause(houseKeeping(test.store))
 		if actualErr != test.expectedErr {
 			t.Errorf("Test %d - actual error is %#v, expected error was %#v",
 				i+1, actualErr, test.expectedErr)