ktrace: Record namei violations with KTR_CAPFAIL
Report namei path lookups while Capsicum violation tracing with
CAPFAIL_NAMEI. vfs caching is also ignored when tracing to mimic
capability mode behavior.
Reviewed by: markj
Approved by: markj (mentor)
MFC after: 1 month
Differential Revision: https://reviews.freebsd.org/D40680