perf bench: Clean up bench/bench.h

Clean up initializers in bench.h:

  - No need to break the line for function prototypes, they are more
    readable in a single line. (even if checkpatch complains about it

  - We try to align definitions / structure fields vertically,
    to make it  all a bit more readable.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Hitoshi Mitake <mitake@dcl.info.waseda.ac.jp>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
LKML-Reference: <1257853855-28934-2-git-send-email-mitake@dcl.info.waseda.ac.jp>