policycoreutils: Fix two host contamination issues

A bad symlink, and a bad reference in a shell script were corrected
by some changes to do_install.

Also do_install was modified to only do the special actions in the target
case, instead of using shell to check what mode we were running in.

jjmac: (2013.09.25)
 Backed out the do_install component temporarily, it no longer seems
 necessary, but I need to confirm this.

Signed-off-by: Mark Hatle <mark.hatle@windriver.com>
Signed-off-by: Joe MacDonald <joe@deserted.net>