net: xen-netback: hash.c: Use built-in RCU list checking

commit f3265971ded98a069ad699b51b8a5ab95e9e5be1 upstream.

list_for_each_entry_rcu has built-in RCU and lock checking.
Pass cond argument to list_for_each_entry_rcu.

Signed-off-by: Madhuparna Bhowmik <madhuparnabhowmik04@gmail.com>
Acked-by: Wei Liu <wei.liu@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Stable-dep-of: 0fa5e94a1811 ("net/xen-netback: prevent UAF in xenvif_flush_hash()")
Signed-off-by: Hagar Hemdan <hagarhem@amazon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>