bug 14537: vkGetPhysicalDeviceImageFormatProperties doesn't express all limitations (WIP)

Use VkSampleCountFlagBits exclusively.  Note that it can be casted to integer.

https://cvs.khronos.org/bugzilla/show_bug.cgi?id=14537
diff --git a/layers/device_limits.cpp b/layers/device_limits.cpp
index 89d5885..257a669 100644
--- a/layers/device_limits.cpp
+++ b/layers/device_limits.cpp
@@ -311,7 +311,7 @@
     get_my_data_ptr(get_dispatch_key(physicalDevice), layer_data_map)->instance_dispatch_table->GetPhysicalDeviceMemoryProperties(physicalDevice, pMemoryProperties);
 }
 
-VK_LAYER_EXPORT void VKAPI vkGetPhysicalDeviceSparseImageFormatProperties(VkPhysicalDevice physicalDevice, VkFormat format, VkImageType type, uint32_t samples, VkImageUsageFlags usage, VkImageTiling tiling, uint32_t* pNumProperties, VkSparseImageFormatProperties* pProperties)
+VK_LAYER_EXPORT void VKAPI vkGetPhysicalDeviceSparseImageFormatProperties(VkPhysicalDevice physicalDevice, VkFormat format, VkImageType type, VkSampleCountFlagBits samples, VkImageUsageFlags usage, VkImageTiling tiling, uint32_t* pNumProperties, VkSparseImageFormatProperties* pProperties)
 {
     get_my_data_ptr(get_dispatch_key(physicalDevice), layer_data_map)->instance_dispatch_table->GetPhysicalDeviceSparseImageFormatProperties(physicalDevice, format, type, samples, usage, tiling, pNumProperties, pProperties);
 }