bonding: Don't destroy bonding master when removing slave via sysfs

It is wrong to destroy a bonding master from a context that uses the sysfs
of that bond. When last IPoIB slave is unenslaved from by writing to a
sysfs file (for bond0 this would be /sys/class/net/bond0/bonding/slaves)
the driver tries to destroy the bond. This is wrong and can lead to a
lockup or a crash.  This fix lets the bonding master stay and relies on
the user to destroy the bonding master if necessary (i.e. before module
ib_ipoib is unloaded)

This patch affects only bonds of IPoIB slaves. Ethernet slaves stay
unaffected.
Signed-off-by: Moni Shoua <monis@voltaire.com>
Signed-off-by: Jay Vosburgh <fubar@us.ibm.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>

drivers/net/bonding/bond_sysfs.c

@@ -350,9 +350,6 @@ static ssize_t bonding_store_slaves(struct device *d,
 		if (dev) {
 			printk(KERN_INFO DRV_NAME ": %s: Removing slave %s\n",
 				bond->dev->name, dev->name);
-			if (bond->setup_by_slave)
-				res = bond_release_and_destroy(bond->dev, dev);
-			else
 				res = bond_release(bond->dev, dev);
 			if (res) {
 				ret = res;