bonding: fix multiple module load problem

bonding: fix multiple module load problem

[ Upstream commit 130aa61a77b8518f1ea618e1b7d214d60b405f10 ]

Some users still load bond module multiple times to create bonding
devices.  This accidentally was broken by a later patch about
the time sysfs was fixed.  According to Jay, it was broken
by:
   commit b8a9787eddb0e4665f31dd1d64584732b2b5d051
   Author: Jay Vosburgh <fubar@us.ibm.com>
   Date:   Fri Jun 13 18:12:04 2008 -0700

     bonding: Allow setting max_bonds to zero

Note: sysfs and procfs still produce WARN() messages when this is done
so the sysfs method is the recommended API.

Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: Jay Vosburgh <fubar@us.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>