nfsd: drop fh_update() from S_IFDIR branch of nfsd_create_locked()

nfsd_create_locked() doesn't need to explicitly call fh_update().
On success (which is the only time that fh_update() matters at all),
nfsd_create_setattr() will be called and it will call fh_update().

This extra call is not harmful, but is not necessary.

Signed-off-by: NeilBrown <neilb@suse.de>
Link: https://lore.kernel.org/r/20250226062135.2043651-3-neilb@suse.de


Signed-off-by: Christian Brauner <brauner@kernel.org>