Fix error state leak in KHR_debug tests
Fix error state leak in KHR_debug tests

Reset error state in KHR_debug callback and log test case variants
after expectError() call to avoid breaking code later in the test due
to lingering error state.

Change-Id: Iec4c67dc10d171a72a9faeb4af800fa8d6e20d79

Omegaphora/external_deqp,googlestadia/VK-GL-CTS,android-ia/platform_external_deqp,chadversary/deqp,maurossi/deqp,android-ia/platform_external_deqp,googlestadia/VK-GL-CTS,KhronosGroup/Vulkan-CTS,MIPS/external-deqp,geekboxzone/lollipop_external_deqp,android-ia/platform_external_deqp,android-ia/platform_external_deqp,KhronosGroup/VK-GL-CTS,chadversary/deqp,MIPS/external-deqp,geekboxzone/mmallow_external_deqp,KhronosGroup/Vulkan-CTS,maurossi/deqp,KhronosGroup/Vulkan-CTS,chadversary/deqp,MIPS/external-deqp,KhronosGroup/Vulkan-CTS,MIPS/external-deqp,geekboxzone/lollipop_external_deqp,chadversary/deqp,chadversary/deqp,CyanogenMod/android_external_deqp,googlestadia/VK-GL-CTS,android-ia/platform_external_deqp,CyanogenMod/android_external_deqp,maurossi/deqp,KhronosGroup/VK-GL-CTS,MIPS/external-deqp,MIPS/external-deqp,KhronosGroup/VK-GL-CTS,maurossi/deqp,Omegaphora/external_deqp,geekboxzone/mmallow_external_deqp,CyanogenMod/android_external_deqp,KhronosGroup/VK-GL-CTS,KhronosGroup/VK-GL-CTS,KhronosGroup/Vulkan-CTS,KhronosGroup/VK-GL-CTS,geekboxzone/mmallow_external_deqp,maurossi/deqp,geekboxzone/lollipop_external_deqp,geekboxzone/mmallow_external_deqp,googlestadia/VK-GL-CTS,Omegaphora/external_deqp,Omegaphora/external_deqp,chadversary/deqp,googlestadia/VK-GL-CTS,KhronosGroup/Vulkan-CTS,Omegaphora/external_deqp,geekboxzone/lollipop_external_deqp,googlestadia/VK-GL-CTS,maurossi/deqp,geekboxzone/lollipop_external_deqp,geekboxzone/lollipop_external_deqp,CyanogenMod/android_external_deqp,android-ia/platform_external_deqp,CyanogenMod/android_external_deqp,geekboxzone/mmallow_external_deqp,geekboxzone/mmallow_external_deqp,Omegaphora/external_deqp