bonding: destroy proc directory only after all bonds are gone

bonding: destroy proc directory only after all bonds are gone

Currently we might arrive to bond_net_exit() with some bonds left (that
were created while the module is unloading). We take care of that by
destroying sysfs (the last possibility to add new bonds) and then
destroying all the remaining bonds.

However, we destroy the /proc/net/bonding directory before destroying those
last bonds, and get a warning that we're trying to destroy a non-empty
proc directory (containing /proc/net/bonding/bondX).

Fix this by moving bond_destroy_proc_dir() after all the bonds are
destroyed, so that we're sure that no bonds exist.

CC: Jay Vosburgh <j.vosburgh@gmail.com>
CC: Andy Gospodarek <andy@greyhouse.net>
Signed-off-by: Veaceslav Falico <vfalico@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>