layers: correct typo vkExternalMemoryHandleTypeFlagsNV

Change-Id: Ifb9a7c7a2ff46580b85a07fa92d8cd44f95e1ce6
diff --git a/vulkan.py b/vulkan.py
index 0b84519..7551be4 100644
--- a/vulkan.py
+++ b/vulkan.py
@@ -1057,7 +1057,7 @@
              Param("VkImageTiling", "tiling"),
              Param("VkImageUsageFlags", "usage"),
              Param("VkImageCreateFlags", "flags"),
-             Param("vkExternalMemoryHandleTypeFlagsNV", "externalHandleType"),
+             Param("VkExternalMemoryHandleTypeFlagsNV", "externalHandleType"),
              Param("VkExternalImageFormatPropertiesNV*", "pExternalImageFormatProperties")]),
     ],
 )