fix the bug of tensorlayer.utils.predict. issues of #288

[xionghhcs]

fix the bug of issues #288

I have fix the bug and the test is as follow:

The relations between data_size and batch_size can be classified into three types:

1. batch_size == data_size;
2. batch_size < data_size
3. batch_size > data_size.

And the second can be further classified into two types:

(a)data_size % batch_size ==0.

(b)data_size % batch_size != 0;

So the test data is as follow:

types	data_size	batch_size	pred_size	pass?
1	100	100	100	YES
2.a	100	10	100	YES
2.b	100	51	100	YES
3	100	101	100	YES