radv: fix incorrect size for primitives generated query

radv: fix incorrect size for primitives generated query

Primitives generated queries write 1 integer, the primitives-generated
count that is incremented every time a primitive emitted to that stream
reaches the transform feedback stage.

Fixes: 1ebf463a5a6 ("radv: implement VK_EXT_primitives_generated_query")
Signed-off-by: Juston Li <justonli@google.com>
Reviewed-by: Yiwei Zhang <zzyiwei@chromium.org>
Reviewed-by: Joshua Ashton <joshua@froggi.es>
Reviewed-by: Samuel Pitoiset <samuel.pitoiset@gmail.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/23915>