crypto: vmx - Fix memory corruption caused by p8_ghash

commit 80da44c29d997e28c4442825f35f4ac339813877 upstream.

This patch changes the p8_ghash driver to use ghash-generic as a fixed
fallback implementation. This allows the correct value of descsize to be
defined directly in its shash_alg structure and avoids problems with
incorrect buffer sizes when its state is exported or imported.

Reported-by: Jan Stancek <jstancek@redhat.com>
Fixes: cc333cd6 ("crypto: vmx - Adding GHASH routines for VMX module")
Signed-off-by: Marcelo Cerri <marcelo.cerri@canonical.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>