This reverts commit 4ed3bb08.

As reported by Sven-Haegar Koch, this patch breaks make headers_check :

   CHECK   include (0 files)
   CHECK   include/asm (54 files)
   /home/haegar/src/2.6.32/linux/usr/include/asm/ptrace.h:5: included file 'linux/linkage.h' is not exported
Signed-off-by: Willy Tarreau <w@1wt.eu>