spirv: Pick up SPIRV-Tools fix for version generation script.
spirv: Pick up SPIRV-Tools fix for version generation script.

This bug would only occur when building spirv-tools outside
of a git repo, such as inside of an SDK install.  When
outside of a git repo, the version generation script
would hit a corner case, making the python script fail.

Change-Id: I5c3a8ce35e8379396e8d19281bbe3331a3f75820

sashinde/VulkanTools,Radamanthe/VulkanSamples,critsec/Vulkan-LoaderAndValidationLayers,KhronosGroup/Vulkan-LoaderAndValidationLayers,Radamanthe/VulkanSamples,KhronosGroup/Vulkan-LoaderAndValidationLayers,elongbug/Vulkan-LoaderAndValidationLayers,Radamanthe/VulkanSamples,elongbug/Vulkan-LoaderAndValidationLayers,KhronosGroup/Vulkan-LoaderAndValidationLayers,KhronosGroup/Vulkan-LoaderAndValidationLayers,critsec/Vulkan-LoaderAndValidationLayers,sashinde/VulkanTools,Radamanthe/VulkanSamples,elongbug/Vulkan-LoaderAndValidationLayers,critsec/Vulkan-LoaderAndValidationLayers,critsec/Vulkan-LoaderAndValidationLayers,elongbug/Vulkan-LoaderAndValidationLayers,Radamanthe/VulkanSamples,sashinde/VulkanTools,Radamanthe/VulkanSamples,sashinde/VulkanTools