xen-netback: remove dead code

The array mmap_pages is never touched in the initialization function. This is
remnant of mapping mechanism, which does not exist upstream. In current
upstream code this array only tracks usage of pages inside netback. Those
pages are allocated when contructing a SKB and passed directly to network
subsystem.

Signed-off-by: Wei Liu <[email protected]>
Acked-by: Ian Campbell <[email protected]>
Signed-off-by: David S. Miller <[email protected]>

Author: Wei Liu

drivers/net/xen-netback/netback.c

@@ -1939,10 +1939,6 @@ static int __init netback_init(void)
 failed_init:
 	while (--group >= 0) {
 		struct xen_netbk *netbk = &xen_netbk[group];
-		for (i = 0; i < MAX_PENDING_REQS; i++) {
-			if (netbk->mmap_pages[i])
-				__free_page(netbk->mmap_pages[i]);
-		}
 		del_timer(&netbk->net_timer);
 		kthread_stop(netbk->task);
 	}