Fix mli example for Owl_dense_matrix_generic.linspace

[mooreryan]

This is a tiny fix for the example for the Owl_dense_matrix_generic.linspace mli file documentation.

The example shows:

[linspace 0. 5. 5] will create a row vector [[0;1;2;3;4;5]]

However, that code produces 0; 1.25; 2.5; 3.75; 5. So I changed the example code to linspace 0. 5. 6 to get the nice 0; 1; 2; 3; 4; 5 output.