LU-3303 test: sanity-quota test_18 incomplete error message

LU-3303 test: sanity-quota test_18 incomplete error message

test_18 is sending the error message to quota_error with
two string literals with no line continuation. quota_error
essentially ignores the second string literal.

Signed-off-by: James Nunez <james.a.nunez@intel.com>
Change-Id: I54e5cccf307349fab072d6fac2832f6bd98a3bfd
Reviewed-on: http://review.whamcloud.com/6302
Tested-by: Hudson
Tested-by: Maloo <whamcloud.maloo@gmail.com>
Reviewed-by: Jian Yu <jian.yu@intel.com>
Reviewed-by: Keith Mannthey <keith.mannthey@intel.com>
Reviewed-by: Oleg Drokin <oleg.drokin@intel.com>