draw: use the prim count for ia primitives

Number of vertices to fetch doesn't always equal the number of input
vertices. To correctly compute the number if IA primitives we need
to use the total number of input vertices, not only those that
need to be fetched.

Signed-off-by: Zack Rusin <zackr@vmware.com>
Reviewed-by: José Fonseca <jfonseca@vmware.com>

src/gallium/auxiliary/draw/draw_pt_fetch_shade_pipeline_llvm.c

@@ -337,10 +337,11 @@ llvm_pipeline_generic( struct draw_pt_middle_end *middle,
       assert(0);
       return;
    }
+
    if (draw->collect_statistics) {
       draw->statistics.ia_vertices += fetch_info->count;
       draw->statistics.ia_primitives +=
-         u_decomposed_prims_for_vertices(prim_info->prim, fetch_info->count);
+         u_decomposed_prims_for_vertices(prim_info->prim, prim_info->count);
       draw->statistics.vs_invocations += fetch_info->count;
    }