[S390] sys_getcpu compat wrapper.

Looking at the new syscall additions, I noticed that
sys_getcpu_wrapper wraps in to sys_tee, in what appears to be
a copy and paste error.  Switch it to point to sys_getcpu..

Signed-off-by: Paul Mundt <lethal@linux-sh.org>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>