Revert "target: Do not special-case loop and iscsi fabric module loads"

Existing lio_dump.py code expects this to be in place for /iscsi.

Revert for now to avoid userspace breakage in lio-utils

This reverts commit fd88a785f9ac5d6be437c528571ccd85cdf2d493.

Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>