Fix error report

There are two kinds of error for func "BuildChaincodeContainer",
Should distinguish them. Eliminated duplcaited content in error
message.

Change-Id: I8ceb7678acf5160cf8a81409ca6d262f6b4d9122
Signed-off-by: jiangyaoguo <[email protected]>

Author: jiangyaoguo

core/container/vm.go

@@ -123,7 +123,7 @@ func (vm *VM) buildChaincodeContainerUsingDockerfilePackageBytes(spec *pb.Chainc
 	}
 	if err := vm.Client.BuildImage(opts); err != nil {
 		vmLogger.Errorf("Failed Chaincode docker build:\n%s\n", outputbuf.String())
-		return fmt.Errorf("Error building Chaincode container: %s", err)
+		return err
 	}
 	return nil
 }

core/devops.go

@@ -113,7 +113,6 @@ func (*Devops) Build(context context.Context, spec *pb.ChaincodeSpec) (*pb.Chain
 
 		codePackageBytes, err = vm.BuildChaincodeContainer(spec)
 		if err != nil {
-			err = fmt.Errorf("Error getting chaincode package bytes: %s", err)
 			devopsLogger.Error(fmt.Sprintf("%s", err))
 			return nil, err
 		}