perf record: Explicity program a default counter

Up until now record has worked on the assumption that type=0, config=0
was a suitable configuration - which it is. Lets make this a little more
explicit and more readable via the use of proper symbols.

[ Impact: cleanup ]

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
LKML-Reference: <new-submission>
Signed-off-by: Ingo Molnar <mingo@elte.hu>