Acq: Fix General Search for Lineitem Attribute-based fields

Acq: Fix General Search for Lineitem Attribute-based fields

Reported by Ben Shum and Kathy Lussier, the Acq General Search interface
was broken in that you couldn't use any of the search fields under
Lineitem Attribute.  This error was indeed introduced by recent commit
55a82b5 as Ben determined, but simply reverting that commit left other
things broken.

This commit actually targets the problem and seems to fix it in my
testing.

Signed-off-by: Lebbeous Fogle-Weekley <lebbeous@esilibrary.com>