fix clrs-07-01-02 solution bug

[chaoyan1037]

Thanks for your sharing solutions.
There is a problem with your solution to the clrs-07-01-02. You can not simply count the numbers that equal to the pivot. Although it can produce the right answer when all numbers are equal. However, it is not a right partition algorithm!

Consider the test case:
[5, 2, 4, 7, 5, 1, 5, 9, 5, 1, 10, 5]

After your original partition it is:
[5, 2, 4, 5, 1, 5, 5, 1, 5, 9, 10, 7]
And the returned pivot index is 6. However, the larger part has a number 1. Obviously, it is not a proper partition algorithm.

I fix the problem by moving the smaller number to the leftmost, and the numbers equal to the pivot after the smaller group. So we can get the right answer to the same test case like:
[2, 4, 1, 1, 5, 5, 5, 5, 5, 9, 10, 7]
And the returned index is also 6.