[gtk+] Revert "Quiet a compiler warning"

[Matthias Clasen <matthiasc src gnome org>]

commit 5009c691ac11a66903a7ede0bda2f2cd02ff9f06
Author: Matthias Clasen <mclasen redhat com>
Date:   Wed Jan 10 07:34:36 2018 -0500

    Revert "Quiet a compiler warning"
    
    This reverts commit 888f289114756daeb80591afd48496fce1d63e8d.

 gdk/gdkvulkancontext.c |    1 -
 1 files changed, 0 insertions(+), 1 deletions(-)
---
diff --git a/gdk/gdkvulkancontext.c b/gdk/gdkvulkancontext.c
index 9841c6c..8bfbd80 100644
--- a/gdk/gdkvulkancontext.c
+++ b/gdk/gdkvulkancontext.c
@@ -149,7 +149,6 @@ gdk_vulkan_strerror (VkResult result)
     case VK_ERROR_INVALID_EXTERNAL_HANDLE_KHR:
     case VK_RESULT_RANGE_SIZE:
     case VK_RESULT_MAX_ENUM:
-    case VK_ERROR_NOT_PERMITTED_EXT:
     default:
       return "Unknown Vulkan error.";
   }