sh: install hard link with same mode as target

Previously when using NO_ROOT we recorded a METALOG entry for the
/.profile hard link with a different mode than the link target, which is
not permitted.

Reviewed by: bapt
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D37476

(cherry picked from commit 1dbb9994d4dd44357976daedcac7d280e8327382)