Revert "Revert "Fix building treeviewfind test.""

Reverts the revert that was needed for 2.7.
This reverts commit 3110c28c.

Change-Id: If7f4d22f3d339842e6a5846e2edb99e2c961a794
Reviewed-by: Eike Ziller <eike.ziller@digia.com>

tests/auto/treeviewfind/treeviewfind.pro

+QTC_PLUGIN_DEPENDS += find
 include(../qttest.pri)
 
-include($$IDE_SOURCE_TREE/src/plugins/find/find.pri)
-
-LIBS *= -L$$IDE_LIBRARY_PATH/QtProject
+LIBS *= -L$$IDE_PLUGIN_PATH/QtProject
 
 SOURCES += \
     tst_treeviewfind.cpp