ease comparison with signed sizeof()

diff --git a/skeletons/OCTET_STRING.c b/skeletons/OCTET_STRING.c
index af41596..75f235e 100644
--- a/skeletons/OCTET_STRING.c
+++ b/skeletons/OCTET_STRING.c
@@ -192,9 +192,8 @@
 		rval = ber_check_tags(opt_codec_ctx, td, ctx,
 			buf_ptr, size, tag_mode, -1,
 			&ctx->left, &tlv_constr);
-		if(rval.code != RC_OK) {
-			RETURN(rval.code);
-		}
+		if(rval.code != RC_OK)
+			return rval;
 
 		if(tlv_constr) {
 			/*
@@ -693,7 +692,7 @@
 	buf = st->buf;
 	end = buf + st->size;
 	for(ss = buf; buf < end; buf++) {
-		int ch = *buf;
+		unsigned int ch = *buf;
 		int s_len;	/* Special encoding sequence length */
 
 		/*