addFunctionCase(): pass parameters by value instead of by reference
addFunctionCase(): pass parameters by value instead of by reference

Passing values always by reference creates problems when passing values
of basic type.

Values can be still passed by reference as long as reference points to
memory that remains live throughout test case execution.

Change-Id: I69c9799b5be7db9ae295283737f9aee3a8dcfdd6

KhronosGroup/Vulkan-CTS,chadversary/deqp,chadversary/deqp,KhronosGroup/VK-GL-CTS,KhronosGroup/VK-GL-CTS,KhronosGroup/VK-GL-CTS,KhronosGroup/Vulkan-CTS,googlestadia/VK-GL-CTS,KhronosGroup/Vulkan-CTS,KhronosGroup/Vulkan-CTS,KhronosGroup/VK-GL-CTS,chadversary/deqp,googlestadia/VK-GL-CTS,chadversary/deqp,googlestadia/VK-GL-CTS,KhronosGroup/Vulkan-CTS,chadversary/deqp,googlestadia/VK-GL-CTS,KhronosGroup/Vulkan-CTS,chadversary/deqp,KhronosGroup/VK-GL-CTS,KhronosGroup/VK-GL-CTS,googlestadia/VK-GL-CTS,googlestadia/VK-GL-CTS