atan2.3: Simplify asterisks

[ziaee]

Summary

Switch asterisk from a (pre ascii) low level roff escape to a normal
ascii asterisk character matching $otherOS. The old roff escape doesn't
render anywhere.

PR: 268421

[cyric_mm.st]

Just a few notes given that I don't know significance of one asterisk form over the other:

1. NetBSD did not remove/replace the \(** macros, they are still there, e.g. https://github.com/NetBSD/src/blob/62c785e59d064070166dab5d2a4492055effba89/lib/libm/man/atan2.3#L150
2. \(** renders just fine for me and is different from the simple ASCII asterisk so I find the "The old roff escape doesn't render anywhere" assertion doubtful.
3. This mathematical asterisk is found in other man pages, and this man page has other mathematical UTF-8 symbols.

[pi]

I tested it on 14.2, and the man page has render issues without this patch, see attached screenshot.{F135333051}

[ziaee]

In D53625#1224405, @cyric_mm.st wrote:

Just a few notes given that I don't know significance of one asterisk form over the other:

1. NetBSD did not remove/replace the \(** macros, they are still there, e.g. https://github.com/NetBSD/src/blob/62c785e59d064070166dab5d2a4492055effba89/lib/libm/man/atan2.3#L150
2. \(** renders just fine for me and is different from the simple ASCII asterisk so I find the "The old roff escape doesn't render anywhere" assertion doubtful.

Hi! Thanks, can you tell us more about that? It Renders just fine... in vt on FreeBSD 14.3-RELEASE with the default font size? In x11 on alacritty terminal in KDE Plasma with the noto fonts? On gnome help 3.30.1?