perf bench: Add "all" pseudo subsystem and "all" pseudo suite

This patch adds a new "all" pseudo subsystem and an "all" pseudo
suite. These are for testing all subsystem and its all suite, or
all suite of one subsystem.

(This patch also contains a few trivial comment fixes for
bench/* and output style fixes. I judged that there are no
necessity to make them into individual patch.)

Example of use:

| % ./perf bench sched all                      # Test all suites of sched subsystem
| # Running sched/messaging benchmark...
| # 20 sender and receiver processes per group
| # 10 groups == 400 processes run
|
|      Total time: 0.414 [sec]
|
| # Running sched/pipe benchmark...
| # Extecuted 1000000 pipe operations between two tasks
|
|      Total time: 10.999 [sec]
|
|       10.999317 usecs/op
|           90914 ops/sec
|
| % ./perf bench all                            # Test all suites of all subsystems
| # Running sched/messaging benchmark...
| # 20 sender and receiver processes per group
| # 10 groups == 400 processes run
|
|      Total time: 0.420 [sec]
|
| # Running sched/pipe benchmark...
| # Extecuted 1000000 pipe operations between two tasks
|
|      Total time: 11.741 [sec]
|
|       11.741346 usecs/op
|           85169 ops/sec
|
| # Running mem/memcpy benchmark...
| # Copying 1MB Bytes from 0x7ff33e920010 to 0x7ff3401ae010 ...
|
|      808.407437 MB/Sec

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>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
LKML-Reference: <1260691319-4683-1-git-send-email-mitake@dcl.info.waseda.ac.jp>
Signed-off-by: Ingo Molnar <mingo@elte.hu>