st/mesa: remove extra calculation of sampler count
This code was originally introduced to fix https://bugs.freedesktop.org/show_bug.cgi?id=53617. The comment says you need to pass NULL in order to unref old views however cso_set_sampler_views() already takes care of old views with the second for loop. Also as of
2355a6441435b8e66a032c44f0794066338e30a3 cso_set_sampler_views() passes the max of the old and new views to the driver for all state trackers making this code obsolete.
Signed-off-by: Timothy Arceri <t_arceri@yahoo.com.au>
Reviewed-by: Brian Paul <brianp@vmware.com>