Create EX_*.3 manual page links to sysexits.3

[0mp]

Summary

Create EX_*.3 manual page links to sysexits.3

Test Plan

export DESTDIR=/tmp/test1234
mkdir -p $DESTDIR

make hierarchy DESTDIR=$DESTDIR
cd share/man/man3
make build
make install DESTDIR=$DESTDIR

# Check /tmp/test1234

[0mp]

I'm looking for a review of 1 thing, really: is it beneficial to actually create those MLINKS.

[0mp]

After a quick chat with some other developers it looks like we would actually want to deprecate sysexits.

[ngie]

In D24224#533296, @0mp wrote:

After a quick chat with some other developers it looks like we would actually want to deprecate sysexits.

Thank you very much for taking the charge in cleaning up manpages, etc!

FWIW, I don't think it would be a good idea to document individual error codes. We don't have manpage links for EINVAL.2, etc, to errno(2).

As long as we're consistent with POSIX's documentation, I believe we're ok with the status quo, which is leaving the individual error codes documented only in sysexits(3).