perf trace: Do not beautify the 'pid' parameter as a simple integer

perf trace: Do not beautify the 'pid' parameter as a simple integer

Leave it alone so that it ends up assigned to SCA_PID via its type,
'pid_t', that will look up the pid on the machine thread rb_tree and
possibly find its COMM.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Milian Wolff <milian.wolff@kdab.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-r7dujgmhtxxfajuunpt1bkuo@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>