crypto: inside-secure - fix the extra cache computation

This patch fixes the extra cache computation when the queued data is a
multiple of a block size. This fixes the hash support in some cases.

Fixes: 809778e0

 ("crypto: inside-secure - fix hash when length is a multiple of a block")
Signed-off-by: Antoine Tenart <antoine.tenart@bootlin.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>