Remove $FreeBSD$: one-line .c pattern

Remove /^[\s*]*__FBSDID\("\$FreeBSD\$"\);?\s*\n/

Fix off-by-one error in fstyp(8) and geom_label(4) that made them use
a single space (" ") as a CD9660 label name when no label was present.
Similar problem was also present in msdosfs label recognition.

PR: 200828
Differential Revision: https://reviews.freebsd.org/D2830
Reviewed by: asomers@, emaste@
MFC after: 2 weeks
Sponsored by: The FreeBSD Foundation

Remove leftovers.

MFC after: 1 month
Sponsored by: The FreeBSD Foundation

Add fstyp(8). This utility, named after its SVR4 counterpart, detects
filesystems. It differs from file(1) in that it gives machine-parseable
output, it outputs filesystem labels, doesn't get confused by other
formats metadata, and runs in Capsicum sandbox.

Differential Revision: https://reviews.freebsd.org/D1255
Relnotes: yes
Sponsored by: The FreeBSD Foundation