camcontrol: In defects make -S actually imply 12-byte command

camcontrol(8) says that -S to start at a different offset implies that
we're using the 12 byte command. But really, we're using the 10-byte
command. Fix this by setting use_12byte for -S.

Sponsored by: Netflix
Reviewed by: mav
Differential Revision: https://reviews.freebsd.org/D40526