Pull up following revision(s) (requested by knakahara in ticket #725):
sys/net/if_l2tp.c: revision 1.21
Fix l2tp(4) alignment check. Pointed out and reviewed by k-goda@IIJ.
The alignment check should be done for the address of m_data instead of
the value of m_data.
XXX pullup-8

(bouyer)