fanotify_mark.2, link.2, mount.2, umount.2, proc.5, cgroups.7, fanotify.7: Terminolog...

fanotify_mark.2, link.2, mount.2, umount.2, proc.5, cgroups.7, fanotify.7: Terminology clean-up: "mount point" ==> "mount"

Many times, these pages use the terminology "mount point", where
"mount" would be better. A "mount point" is the location at which
a mount is attached. A "mount" is an association between a
filesystem and a mount point.

Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>