perf target: Rename functions to avoid double negation

perf target: Rename functions to avoid double negation

Rename perf_target__no_{cpu,task} to perf_target__has_{cpu,task} because
it's more intuitive and easy to parse (for human beings) when used with
negation.

The names are came out from David Ahern.  It is intended to be a
mechanical substitution without any functional change.

The perf_target__none remains unchanged since I couldn't find a right
name and it is hardly used with negation.

Signed-off-by: Namhyung Kim <namhyung.kim@lge.com>
Suggested-by: David Ahern <dsahern@gmail.com>
Suggested-by: Ingo Molnar <mingo@kernel.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Namhyung Kim <namhyung@gmail.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1337161549-9870-1-git-send-email-namhyung.kim@lge.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>