[BusyBox] more online doc fixes, util-linux/ directory

[Robert P. J. Day]

fdisk:

 	the online docs are incomplete in both the synopsis and list of
	options:

	while ((c = getopt(argc, argv, "b:C:H:lS:uvV"
mkswap:

	docs don't mention "-f" option for force

and that's pretty much it for now.

rday