Multitheaded tests showed that the icv buffer in the current ghash
implementation is not handled correctly. A move of this working ghash
buffer value to the descriptor context fixed this. Code is tested and
verified with an multithreaded application via af_alg interface.

Cc: stable@vger.kernel.org
Signed-off-by: NHarald Freudenberger <freude@linux.vnet.ibm.com>
Signed-off-by: NGerald Schaefer <geraldsc@linux.vnet.ibm.com>
Reported-by: NHerbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au>