Remove -m (update) from ldconfig -32 & -soft invocation on startup.

Remove -m (update) from ldconfig -32 & -soft invocation on startup.

Since r154114 which introduced ldconfig_local32_dirs, ldconfig -32 was
called with -m. This means that ld-elf32.so.hints paths set is not
cleared for compat32 on boot, unlike ld,so,hints.  Same -m was used in
r294295 for ld-elf-soft.so.hints on arm.  The patch fixes the
asymmetry.

Noted by:	Andreas Longwitz <longwitz@incore.de>
Reviewed by:	brooks, emaste, imp
Discussed with:	bdrewery
Sponsored by:	The FreeBSD Foundation
Approved by:	re (gjb)
MFC after:	1 week
Differential revision:	https://reviews.freebsd.org/D17331