gfs: constify xattr_handler

Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/fs/gfs2/super.h b/fs/gfs2/super.h
index 3df60f2..a046468 100644
--- a/fs/gfs2/super.h
+++ b/fs/gfs2/super.h
@@ -54,7 +54,7 @@
 extern const struct export_operations gfs2_export_ops;
 extern const struct super_operations gfs2_super_ops;
 extern const struct dentry_operations gfs2_dops;
-extern struct xattr_handler *gfs2_xattr_handlers[];
+extern const struct xattr_handler *gfs2_xattr_handlers[];
 
 #endif /* __SUPER_DOT_H__ */