[FAB-5365] Fix bad error in peer CLI Deliver

The peer CLI currently attempts to print the error status returned by
the orderer's Deliver gRPC method.  However, the log statement
inappropriately uses the '%T' modifier, and prints the type of the
status, not the actual status code inside it.  Consequently, all deliver
errors read the same uninformative error message:

    Got Status:*orderer.DeliverResponse_Status

This CR fixes this log statement to include the status code instead, and
additionally enhances the other error messages with pertitent
information.

Change-Id: I5a3e1dec574bfab178550cf67bc96a66f1896d5b
Signed-off-by: Jason Yellick <jyellick@us.ibm.com>

peer/channel/deliverclient.go

@@ -82,14 +82,14 @@ func (r *deliverClient) readBlock() (*common.Block, error) {
 
 	switch t := msg.Type.(type) {
 	case *ab.DeliverResponse_Status:
-		logger.Debugf("Got status:%T ", t)
-		return nil, fmt.Errorf("can't read the block")
+		logger.Debugf("Got status: %v", t)
+		return nil, fmt.Errorf("can't read the block: %v", t)
 	case *ab.DeliverResponse_Block:
-		logger.Debugf("Received block:%v ", t.Block.Header.Number)
+		logger.Debugf("Received block: %v", t.Block.Header.Number)
 		r.client.Recv() // Flush the success message
 		return t.Block, nil
 	default:
-		return nil, fmt.Errorf("response error")
+		return nil, fmt.Errorf("response error: unknown type %T", t)
 	}
 }