ctf: fix various dreadful typos in the ctf_archive format comments

When defining a format it helps to a) get the endianness right when you
explicitly state what it is and b) define things in terms of fields that
exist rather than fields that don't.

(A bunch of changes of names during implementation were not reflected in
these comments...)

Thanks to Jose "Eye of the Eagle" Marchesi for spotting these.

include/
	* ctf.h (struct ctf_archive) [ctfa_ctfs]: The size element of
	this is in little-endian byte order, not network byte order.
	(struct ctf_archive_modent): This is positioned right after the
	end fo the struct ctf_archive, not at the offset of a
	nonexistent field.  The number of elements in the array depends
	on ctfa_ndicts, not another nonexistent field.