Restore the 'beforeinstall' for chpass(1), so files with the

Restore the 'beforeinstall' for chpass(1), so files with the
schg flag are handled before being replaced by a symbolic link.

Fix passwd(1)/yppasswd(1) schg issue similarly to chpass(1).

Note:  These are likely temporary fixes while identifying any
remaining files that are not marked as 'flags=schg' via mtree(8).

Sponsored by:	The FreeBSD Foundation