perf evlist: Move destruction of maps to evlist destructor

perf evlist: Move destruction of maps to evlist destructor

Instead of requiring tools to do an extra destructor call just before
calling perf_evlist__delete.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/n/tip-0jd2ptzyikxb5wp7inzz2ah2@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>