Fix requires concept

Author: solidpixel

generator/generate_vulkan_common.py

@@ -586,7 +586,7 @@ def generate_instance_queries(
         lines.append('/* Test for user_tag availability. */')
         decl = f'template <typename T>\n' \
                f'concept hasLayerPtr_{command.name} = ' \
-               f'requires {{ layer_{command.name}<user_tag>; }};'
+               f'requires {{ layer_{command.name}<T>(); }};'
         lines.append(decl)
         lines.append('')
 
@@ -918,7 +918,7 @@ def generate_device_queries(
         lines.append('/* Test for user_tag availability. */')
         decl = f'template <typename T>\n' \
                f'concept hasLayerPtr_{command.name} = ' \
-               f'requires {{ layer_{command.name}<user_tag>; }};'
+               f'requires {{ layer_{command.name}<T>(); }};'
         lines.append(decl)
         lines.append('')