vulkan: remove FFVkBuffer.stage and access

Keeping global state for every buffer is unncessary and possibly
suboptimal.

libavutil/vulkan.c

@@ -1309,8 +1309,6 @@ int ff_vk_get_pooled_buffer(FFVulkanContext *ctx, AVBufferPool **buf_pool,
         return AVERROR(ENOMEM);
 
     data = (FFVkBuffer *)ref->data;
-    data->stage = VK_PIPELINE_STAGE_2_ALL_COMMANDS_BIT;
-    data->access = VK_ACCESS_2_NONE;
 
     if (data->size >= size)
         return 0;

libavutil/vulkan.h

@@ -91,10 +91,6 @@ typedef struct FFVkBuffer {
     size_t size;
     VkDeviceAddress address;
 
-    /* Local use only */
-    VkPipelineStageFlags2 stage;
-    VkAccessFlags2 access;
-
     /* Only valid when allocated via ff_vk_get_pooled_buffer with HOST_VISIBLE or
      * via ff_vk_host_map_buffer */
     uint8_t *mapped_mem;