tweaks: use a more direct call when a single linestruct is deleted

src/nano.c

@@ -412,7 +412,7 @@ void ingraft_buffer(linestruct *somebuffer)
 	filepart = partition_buffer(openfile->current, openfile->current_x,
 								openfile->current, openfile->current_x);
 	edittop_inside = (openfile->edittop == openfile->filetop);
-	free_lines(openfile->filetop);
+	delete_node(openfile->filetop);
 
 	/* Put the top and bottom of the current buffer at the top and
 	 * bottom of the passed buffer. */

src/utils.c

@@ -442,7 +442,7 @@ void remove_magicline(void)
 	if (openfile->filebot->data[0] == '\0' &&
 				openfile->filebot != openfile->filetop) {
 		openfile->filebot = openfile->filebot->prev;
-		free_lines(openfile->filebot->next);
+		delete_node(openfile->filebot->next);
 		openfile->filebot->next = NULL;
 		openfile->totsize--;
 	}