bonding: remove unwanted lock for bond_store_primaryxxx()

The bond_select_active_slave() will not release and acquire
bond lock, so it is no need to read the bond lock for them,
and the bond_store_primaryxxx() is already in RTNL, so remove the
unwanted lock.

Suggested-by: Jay Vosburgh <fubar@us.ibm.com>
Suggested-by: Veaceslav Falico <vfalico@redhat.com>
Signed-off-by: Ding Tianhong <dingtianhong@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/bonding/bond_sysfs.c

@@ -878,7 +878,6 @@ static ssize_t bonding_store_primary(struct device *d,
 	if (!rtnl_trylock())
 		return restart_syscall();
 	block_netpoll_tx();
-	read_lock(&bond->lock);
 	write_lock_bh(&bond->curr_slave_lock);
 
 	if (!USES_PRIMARY(bond->params.mode)) {
@@ -918,7 +917,6 @@ static ssize_t bonding_store_primary(struct device *d,
 		bond->dev->name, ifname, bond->dev->name);
 out:
 	write_unlock_bh(&bond->curr_slave_lock);
-	read_unlock(&bond->lock);
 	unblock_netpoll_tx();
 	rtnl_unlock();
 
@@ -966,11 +964,9 @@ static ssize_t bonding_store_primary_reselect(struct device *d,
 		new_value);
 
 	block_netpoll_tx();
-	read_lock(&bond->lock);
 	write_lock_bh(&bond->curr_slave_lock);
 	bond_select_active_slave(bond);
 	write_unlock_bh(&bond->curr_slave_lock);
-	read_unlock(&bond->lock);
 	unblock_netpoll_tx();
 out:
 	rtnl_unlock();