loader: Update calling conventions on instance extension functions
diff --git a/loader/debug_report.c b/loader/debug_report.c
index 40a4b5b..497860e 100644
--- a/loader/debug_report.c
+++ b/loader/debug_report.c
@@ -65,7 +65,7 @@
     }
 }
 
-static VkResult debug_report_DbgCreateMsgCallback(
+static VkResult VKAPI debug_report_DbgCreateMsgCallback(
         VkInstance instance,
         VkFlags msgFlags,
         const PFN_vkDbgMsgCallback pfnMsgCallback,
@@ -93,7 +93,7 @@
     return result;
 }
 
-static VkResult debug_report_DbgDestroyMsgCallback(
+static VkResult VKAPI debug_report_DbgDestroyMsgCallback(
         VkInstance instance,
         VkDbgMsgCallback msg_callback)
 {