crypto: picoxcell - set [src|dst]_nents and nents as signed int

The unsigned int variables [src|dst]_nents and nents 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: f051f95eb47b ("crypto: picoxcell - check return value of sg_nents_for_len")
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: LABBE Corentin <clabbe.montjoie@gmail.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

drivers/crypto/picoxcell_crypto.c

@@ -289,10 +289,11 @@ static struct spacc_ddt *spacc_sg_to_ddt(struct spacc_engine *engine,
 					 enum dma_data_direction dir,
 					 dma_addr_t *ddt_phys)
 {
-	unsigned nents, mapped_ents;
+	unsigned mapped_ents;
 	struct scatterlist *cur;
 	struct spacc_ddt *ddt;
 	int i;
+	int nents;
 
 	nents = sg_nents_for_len(payload, nbytes);
 	if (nents < 0) {
@@ -326,7 +327,7 @@ static int spacc_aead_make_ddts(struct aead_request *areq)
 	struct spacc_engine *engine = req->engine;
 	struct spacc_ddt *src_ddt, *dst_ddt;
 	unsigned total;
-	unsigned int src_nents, dst_nents;
+	int src_nents, dst_nents;
 	struct scatterlist *cur;
 	int i, dst_ents, src_ents;