ceph: fix -EOLDSNAPC handling

Need to drop cap reference before retry. Besides, it's better to
redo file write checks for each retry because we re-lock inode.

Signed-off-by: "Yan, Zheng" <zyan@redhat.com>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
1 file changed