Revert "Revert "xen-swiotlb: fix the check condition for xen_swiotlb_free_coherent""

Revert "Revert "xen-swiotlb: fix the check condition for xen_swiotlb_free_coherent""

This reverts commit 4dbc2ddc8d51dd616b95d868b0223d102428b995.

The root cause of panic in commit 7fc30809bfa8 ("xen-swiotlb: fix the check
condition for xen_swiotlb_free_coherent") is identified. Enable this patch
again as the fix is already available.

The Reviewed-by by for the revert is only to sync the uek4 code with upstream.
It is not clear at the moment whether upstream code is correct.

Orabug: 28258102

Signed-off-by: Dongli Zhang <dongli.zhang@oracle.com>
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Signed-off-by: Brian Maly <brian.maly@oracle.com>