vo_gpu: vulkan: fix the buffer size on partial upload

This was pased on the texture height, which was a mistake. In some cases
it could exceed the actual size of the buffer, leading to a vulkan API
error. This didn't seem to cause any problems in practice, since a
too-large synchronization is just bad for performance and shouldn't do
any harm internally, but either way, it was still undefined behavior to
submit a barrier outside of the buffer size.

Fix the calculation, thus fixing this issue.

video/out/vulkan/ra_vk.c

@@ -886,6 +886,7 @@ static bool vk_tex_upload(struct ra *ra,
             struct mp_rect *rc = params->rc;
             region.imageOffset = (VkOffset3D){rc->x0, rc->y0, 0};
             region.imageExtent = (VkExtent3D){mp_rect_w(*rc), mp_rect_h(*rc), 1};
+            region.bufferImageHeight = region.imageExtent.height;
         }
     }