crypto: ccree - do not copy zero size MLLI table

When we are given a 0 sized cryptlen and assoclen in
a scatterlist with two entries we were falsely trying to
create a zero length MLLI table, causing the HW to choke.
Don't try to copy a zero sized MLLI table.

Signed-off-by: Gilad Ben-Yossef <gilad@benyossef.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>