v3dv: reset subpass index at render pass end

Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/6766>

src/broadcom/vulkan/v3dv_cmd_buffer.c

@@ -1843,8 +1843,9 @@ v3dv_CmdEndRenderPass(VkCommandBuffer commandBuffer)
    }
 
    /* We are no longer inside a render pass */
-   state->pass = NULL;
    state->framebuffer = NULL;
+   state->pass = NULL;
+   state->subpass_idx = -1;
 }
 
 VkResult