Fix double-free with stylesheets containing entity nodes

Fix broken logic to make sure that entity nodes are deleted from the
stylesheet. Note that stylesheets parsed with XML_PARSE_NOENT, which
is included in XSLT_PARSE_OPTIONS, aren't affected.

Found by OSS-Fuzz.

libxslt/xslt.c

@@ -3656,9 +3656,6 @@
 	    (!xsltCheckExtURI(style, cur->ns->href))) {
 	    goto skip_children;
 	} else if (cur->children != NULL) {
-	    if ((cur->children->type != XML_ENTITY_DECL) &&
-		(cur->children->type != XML_ENTITY_REF_NODE) &&
-		(cur->children->type != XML_ENTITY_NODE)) {
 	    cur = cur->children;
 	    continue;
 	}
@@ -3662,7 +3659,6 @@
 	    cur = cur->children;
 	    continue;
 	}
-	}
 
 skip_children:
 	if (cur->next != NULL) {