Newbie task: Fix a build regression

[Richard Weinberger]

Hi!

On linux-next (next-20140530) the UML out-of-tree build is broken.
---cut---
rw at azrael:~/linux-next (next-20140530)> make defconfig ARCH=um O=/mnt/o
  GEN     ./Makefile
*** Default configuration is based on 'x86_64_defconfig'
#
# configuration written to .config
#
rw at azrael:~/linux-next (next-20140530)> LANG=C make -j 8 linux ARCH=um O=/mnt/o
  CHK     include/generated/uapi/linux/version.h
  CHK     include/config/kernel.release
  GEN     ./Makefile
  Using /home/rw/linux-next as source for kernel
  CHK     include/generated/utsrelease.h
  UPD     include/generated/utsrelease.h
  CC      arch/x86/um/user-offsets.s
/home/rw/linux-next/arch/x86/um/user-offsets.c:21:29: fatal error:
asm/syscalls_64.h: No such file or directory
compilation terminated.
make[2]: *** [arch/x86/um/user-offsets.s] Error 1
make[1]: *** [arch/x86/um/user-offsets.s] Error 2
make: *** [sub-make] Error 2
---cut---

Fixing this should be easy, so I offer this as a newbie task.

1. Find out which commit broke the build (i.e. using git bisect)
2. Fix the build
3. Send me a patch

-- 
Thanks,
//richard