ceph_fs.h: add 32 bits extended num_retry and num_fwd support

ceph_fs.h: add 32 bits extended num_retry and num_fwd support

To make sure both the num_retry and num_fwd in all the structs have
the same type, which is 32 bits.

And also for old cephs and clients they still could use the 8 bits
members.

Fixes: https://tracker.ceph.com/issues/57854
Signed-off-by: Xiubo Li <xiubli@redhat.com>
(cherry picked from commit cbd7e3040208a5d89b9a95d4161dbd908da51079)