crypto: omap-sham - fix very small data size handling

With very small data sizes, the whole data can end up in the xmit
buffer. This code path does not set the sg_len properly which causes the
core dma framework to crash. Fix by adding the proper size in place.
Also, the data length must be a multiple of block-size, so extend the
DMA data size while here.
Signed-off-by: Tero Kristo <t-kristo@ti.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

drivers/crypto/omap-sham.c

@@ -752,9 +752,11 @@ static int omap_sham_align_sgs(struct scatterlist *sg,
 
 	if (!sg || !sg->length || !nbytes) {
 		if (bufcnt) {
+			bufcnt = DIV_ROUND_UP(bufcnt, bs) * bs;
 			sg_init_table(rctx->sgl, 1);
 			sg_set_buf(rctx->sgl, rctx->dd->xmit_buf, bufcnt);
 			rctx->sg = rctx->sgl;
+			rctx->sg_len = 1;
 		}
 
 		return 0;