dump: call cpu_init() in pre-dump

It's required for dumping fpu state

[root@avagin-fc19-cr crtools]# bash  test/zdtm.sh  -d -P -i 2  static/fpu00
Execute zdtm/live/static/fpu00
./fpu00 --pidfile=fpu00.pid --outfile=fpu00.out
Dump 8411
Dump 8411
Check results 8411
01:29:30.550:  8411: FAIL: fpu00.c:78: 0.806165 != -nan
 (errno = 11 (Resource temporarily unavailable))

Signed-off-by: Andrey Vagin <avagin@openvz.org>
Acked-by: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>