fix usages of scoped? to check rails 3 style x_values

Change-Id: I75142f6a2d758e1f672a79ecf3c7da69ba5c8f30
Reviewed-on: https://gerrit.instructure.com/29558
Tested-by: Jenkins <jenkins@instructure.com>
Reviewed-by: Ryan Florence <ryanf@instructure.com>
Product-Review: Cody Cutrer <cody@instructure.com>
QA-Review: Cody Cutrer <cody@instructure.com>