undo previous, now sockstat works without privs

turn on fortify since it is setgid (from scole_mail)

RR/54971: scole_mail: sockstat command output incorrect for normal
user As the PR hints, it is not enough to have kern.expose_address=1
to see kernel addresses, we also need to have the PK_KMEM bit s

RR/54971: scole_mail: sockstat command output incorrect for normal
user As the PR hints, it is not enough to have kern.expose_address=1
to see kernel addresses, we also need to have the PK_KMEM bit set
which we achieve by installing sockstat setgid kmem and opening
and closing /dev/mem. (/usr/src/sys/kern/kern_proc.c:311). It is
unfortunate that we need to give the program more privilege, to
prove to the kernel that we have the privilege to see the data.

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sockstat: Add indirection of symbols to remove clash with sanitizers

Add indirection and symbol renaming under MKSANITIZER for the linked in
version of sysctlgetmibinfo and sysctlnametomib.

support rump.sockstat

Query the v6 sockets only if USE_INET6 != "no". Patch provided by Jukka Salmi
on PR#30963.

ok atatat@

Add a sockstat(1) command that can list open sockets and the processes
that own them. The implementation concept and man page came largely
from FreeBSD, but the program is fresh.