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>