Fix regression with /i caused by r303047

'\n' was specifically added to -e arguments prior to r303047. Restore
historical behavior which in turn fixes usr.sbin/etcupdate/preworld_test:main .

The fix is being committed to address the issue in the short term and may be
iterated upon as noted in bug 211399

Discussed with: mi, pfg
Differential Revision: https://reviews.freebsd.org/D7368
PR: 195929, 211399 [*]
MFC after: 18 days
X-MFC with: r303047
Reported by: Jenkins
Sponsored by: EMC / Isilon Storage Division