Defect in XCU tail

[Geoff Clare <gwc@xxxxxxxxxxxxx>]

@ page 900 line 34951-34952 section tail comment [gwc tail rationale]

Problem:

Defect code :  1. Error

The last paragraph of the rationale for the tail utility seems to be
disconnected from something it was meant to refer back to.

It doesn't appear to match up with anything earlier in the rationale,
so it is not simply a case of some more text having been added in
between two connected paragraphs.  Perhaps something got deleted,
but the original POSIX.2 rationale was the same, so the deletion
would have been during the draft stage.

Unless someone has some old POSIX.2 drafts and can work out what the
last paragraph was referring back to, we might as well just delete it.

Action:

Delete "This was changed to the current form based on comments noting
that -c was almost never used without specifying a number and that
there was no need to specify -l if -n number was given."