bonding: correctly handle out of range parameters for lp_interval

We didn't correctly check cases where the value for lp_interval is not
within the legal range due to a missing table terminator.

This would let userspace trigger a kernel panic by specifying a value out
of range:

	echo -1 > /sys/devices/virtual/net/bond0/bonding/lp_interval

Introduced by commit 4325b374 ("bonding: convert lp_interval to use
the new option API").

Acked-by: Nikolay Aleksandrov <nikolay@redhat.com>
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>