drm/xe: Fix dma-buf attachment leak in xe_gem_prime_import()

In the Linux kernel, the following vulnerability has been resolved: drm/xe: Fix dma-buf attachment leak in xe_gem_prime_import() When xe_dma_buf_init_obj() fails, the attachment from dma_buf_dynamic_attach() is not detached. Add dma_buf_detach() before returning the error. Note: we cannot use goto out_err here because xe_dma_buf_init_obj() already frees bo on failure, and out_err would double-free it. (cherry picked from commit a828eb185aac41800df8eae4b60501ccc0dbbe51)