bonding: fix parameter parsing

	My last fix (commit ece95f7f)
didn't handle one case correctly.  This resolves that, and it will now
correctly parse parameters with arbitrary white space, and either text
names or mode values.

Signed-off-by: Jay Vosburgh <fubar@us.ibm.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
Signed-off-by: David S. Miller <davem@davemloft.net>