ceph: remove redundant io_iter_advance()
ceph: remove redundant io_iter_advance()

ceph_sync_read and generic_file_read_iter() have already advanced the
IO iterator.

Signed-off-by: Yan, Zheng <5a3288024fcad83740d827e0862f4c1e6f28e7bf@redhat.com>

KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs