v3dv: don't leak variant QPU when pipeline compile fails

Typically we free them when we upload the QPU code from the variant
to the assembly BO in the pipeline, however, if there is an error
during pipeline compilation that may not happen and we would leak
the QPU code from the variants.

Reviewed-by: Alejandro Piñeiro <apinheiro@igalia.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/16370>

src/broadcom/vulkan/v3dv_pipeline.c

@@ -94,6 +94,8 @@ v3dv_shader_variant_destroy(struct v3dv_device *device,
    /* The assembly BO is shared by all variants in the pipeline, so it can't
     * be freed here and should be freed with the pipeline
     */
+   if (variant->qpu_insts)
+      free(variant->qpu_insts);
    ralloc_free(variant->prog_data.base);
    vk_free(&device->vk.alloc, variant);
 }