crypto: nx - Fix RCU warning in nx842_OF_upd_status

The function nx842_OF_upd_status triggers a sparse RCU warning when
it directly dereferences the RCU-protected devdata.  This appears
to be an accident as there was another variable of the same name
that was passed in from the caller.

After it was removed (because the main purpose of using it, to
update the status member was itself removed) the global variable
unintenionally stood in as its replacement.

This patch restores the devdata parameter.

Fixes: 90fd73f9 ("crypto: nx - remove pSeries NX 'status' field")
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>