setup_or_cleanup_iscsi: Use utils_selinux

Rather than blindly clearing/setting the selinux enforce value
first check if it is actually set to enforcing before lowering
to permissive.  Then after done, don't blindly set back to
enforcing unless it was set prior.
Adjust error message text for Iscsi
Merge pull request #1463 from jferlan/iscsi_fix

iscsi: Don't override selinux settings