bug 15045: vkGetPhysicalDeviceImageFormatProperties for unsupported formats (WIP)

Change the return type of vkGetPhysicalDeviceImageFormatProperties.

https://cvs.khronos.org/bugzilla/show_bug.cgi?id=15045
diff --git a/loader/loader.h b/loader/loader.h
index f356a79..f91e86c 100644
--- a/loader/loader.h
+++ b/loader/loader.h
@@ -290,7 +290,8 @@
         VkFormat                                format,
         VkFormatProperties*                     pFormatInfo);
 
-void VKAPI loader_GetPhysicalDeviceImageFormatProperties(VkPhysicalDevice                        physicalDevice,
+VkResult VKAPI loader_GetPhysicalDeviceImageFormatProperties(
+        VkPhysicalDevice                        physicalDevice,
         VkFormat                                format,
         VkImageType                             type,
         VkImageTiling                           tiling,