Revert "crypto: talitos - convert to use be16_add_cpu()"

commit 69d9cd8c upstream.

This reverts commit 7291a932.

The conversion to be16_add_cpu() is incorrect in case cryptlen is
negative due to premature (i.e. before addition / subtraction)
implicit conversion of cryptlen (int -> u16) leading to sign loss.

Cc: Wei Yongjun <yongjun_wei@trendmicro.com.cn>
Signed-off-by: Horia Geanta <horia.geanta@freescale.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Luis Henriques <luis.henriques@canonical.com>

drivers/crypto/talitos.c

@@ -927,7 +927,8 @@ static int sg_to_link_tbl(struct scatterlist *sg, int sg_count,
 		sg_count--;
 		link_tbl_ptr--;
 	}
-	be16_add_cpu(&link_tbl_ptr->len, cryptlen);
+	link_tbl_ptr->len = cpu_to_be16(be16_to_cpu(link_tbl_ptr->len)
+					+ cryptlen);
 
 	/* tag end of link table */
 	link_tbl_ptr->j_extent = DESC_PTR_LNKTBL_RETURN;