crypto: sahara - set nb_[in|out]_sg as signed int

The two unsigned int variables nb_in_sg and nb_out_sg can be assigned
signed value (-EINVAL) from sg_nents_for_len().
Furthermore they are used only by dma_map_sg and dma_unmap_sg which wait
for an signed int, so they must be set as int.

Fixes: 6c2b74d4 ("crypto: sahara - check return value of sg_nents_for_len")
Reported-by: NDan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: NLABBE Corentin <clabbe.montjoie@gmail.com>
Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au>

drivers/crypto/sahara.c

@@ -228,9 +228,9 @@ struct sahara_dev {
 
 	size_t			total;
 	struct scatterlist	*in_sg;
-	unsigned int		nb_in_sg;
+	int		nb_in_sg;
 	struct scatterlist	*out_sg;
-	unsigned int		nb_out_sg;
+	int		nb_out_sg;
 
 	u32			error;
 };