nfs: add a tracepoint to nfs_inode_detach_delegation_locked

We have tracepoints for setting a delegation and reclaiming them. Add a
tracepoint for when the delegation is being detached from the inode.

Reviewed-by: Benjamin Coddington <bcodding@redhat.com>
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Link: https://lore.kernel.org/r/20250618-nfs-tracepoints-v2-2-540c9fb48da2@kernel.org


Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>