We pass a pointer to the flags to dabitsysctl, not an integer. Adjust the

We pass a pointer to the flags to dabitsysctl, not an integer. Adjust the
handler to accept a poitner to a u_int. To make the type of the softc flags
stable and defined, make it a u_int. Cast the enum types to u_int for arg2 so
when passing to dabitsysctl it's a u_int.

Noticed by: emax@
Differential Revision: https://reviews.freebsd.org/D23785