vkcube: Fix alpha enum type

Change-Id: Id85e0228aeb834de37586fa5d8d334ddc1c7371e
diff --git a/cube/cube.c b/cube/cube.c
index f8da4f6..373b08f 100644
--- a/cube/cube.c
+++ b/cube/cube.c
@@ -3027,8 +3027,8 @@
     VkDisplayPlaneCapabilitiesKHR planeCaps;
     vkGetDisplayPlaneCapabilitiesKHR(demo->gpu, mode_props.displayMode, plane_index, &planeCaps);
     // Find a supported alpha mode
-    VkCompositeAlphaFlagBitsKHR alphaMode = VK_DISPLAY_PLANE_ALPHA_OPAQUE_BIT_KHR;
-    VkCompositeAlphaFlagBitsKHR alphaModes[4] = {
+    VkDisplayPlaneAlphaFlagBitsKHR alphaMode = VK_DISPLAY_PLANE_ALPHA_OPAQUE_BIT_KHR;
+    VkDisplayPlaneAlphaFlagBitsKHR alphaModes[4] = {
         VK_DISPLAY_PLANE_ALPHA_OPAQUE_BIT_KHR,
         VK_DISPLAY_PLANE_ALPHA_GLOBAL_BIT_KHR,
         VK_DISPLAY_PLANE_ALPHA_PER_PIXEL_BIT_KHR,