[patch] ieee.c & elf64-ia64.c: Fix comment typos.

[Kazu Hirata]

Hi Nick,

> Since you are fixing the comment in ieee.c, you might as well fix up
> the grammar in it as well.  In fact the comment itself is rather
> poorly written, so may I suggest this alternative:

I forgot replacing the comment, so I did a second commit.  I also did
an unsual thing: changing ChangeLog instead of prepending.  I hope
this is OK.

Thanks,

Kazu Hirata