perf trace beauty mmap: Add missing MADV_FREE

tools/perf/trace/beauty/mmap.c forgets to check MADV_FREE.
This patch fixes it.

Signed-off-by: Wang Nan <wangnan0@huawei.com>
Cc: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Cc: Zefan Li <lizefan@huawei.com>
Cc: pi3orama@163.com
Link: http://lkml.kernel.org/r/1473850649-83389-2-git-send-email-wangnan0@huawei.com


Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>