vbo: take into account the size when printing VAO elements

vbo: take into account the size when printing VAO elements

When using print_draw_arrays for debugging, we were printing an "n"
amount of vertex but that meant not to print all the size in the "n"
vertex, depending on the stride used.

Now we print the whole size in the "n" vertex.

Cc: Mathias Fröhlich <mathias.froehlich@web.de>
Cc: Brian Paul <brianp@vmware.com>
Signed-off-by: Andres Gomez <agomez@igalia.com>
Reviewed-by: Mathias Fröhlich <mathias.froehlich@web.de>