crypto: acomp - Fix synchronous acomp chaining fallback

The synchronous acomp fallback code path is broken because the
completion code path assumes that the state object is always set
but this is only done for asynchronous algorithms.

First of all remove the assumption on the completion code path
by passing in req0 instead of the state.  However, also remove
the conditional setting of the state since it's always in the
request object anyway.

Fixes: b67a0260 ("crypto: acomp - Add request chaining and virtual addresses")
Reported-by: Giovanni Cabiddu <giovanni.cabiddu@intel.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>