xdiff: cleanup some warnings

src/xdiff/xdiffi.c

@@ -544,6 +544,8 @@ static int xdl_call_hunk_func(xdfenv_t *xe, xdchange_t *xscr, xdemitcb_t *ecb,
 {
 	xdchange_t *xch, *xche;
 
+	(void)xe;
+
 	for (xch = xscr; xch; xch = xche->next) {
 		xche = xdl_get_hunk(&xch, xecfg);
 		if (!xch)

src/xdiff/xemit.c

@@ -90,7 +90,7 @@ xdchange_t *xdl_get_hunk(xdchange_t **xscr, xdemitconf_t const *xecfg)
 		} else if (distance < max_ignorable && xch->ignore) {
 			ignored += xch->chg2;
 		} else if (lxch != xchp &&
-			   xch->i1 + ignored - (lxch->i1 + lxch->chg1) > max_common) {
+			   xch->i1 + ignored - (lxch->i1 + lxch->chg1) > (unsigned long)max_common) {
 			break;
 		} else if (!xch->ignore) {
 			lxch = xch;