ktrace: Record syscall violations with KTR_CAPFAIL
Report syscalls that are not allowed in capability mode with
CAPFAIL_SYSCALL.
Reviewed by: markj
Approved by: markj (mentor)
MFC after: 1 month
Differential Revision: https://reviews.freebsd.org/D40678
(cherry picked from commit 05296a0ff615566d25c77c5e6619b08724d2eecb)