It's 2015, and some people are still trying to use fdisk and then
go asking what debug flags to set for GEOM to make it work. Advice
them to use gpart(8) instead.

Something similar should probably done with disklabel,
but I need to rewrite the disklabel examples first.

Reviewed by: wblock@
MFC after: 1 month
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D3315