perf probe: Add __return suffix for return events

Add __return suffix for function return events automatically. Without
this, user have to give --force option and will see the number suffix
for each event like "function_1", which is not easy to recognize.
Instead, this adds __return suffix to it automatically.  E.g.

  =====
  # ./perf probe -x /lib64/libc-2.25.so 'malloc*%return'
  Added new events:
    probe_libc:malloc_printerr__return (on malloc*%return in /usr/lib64/libc-2.25.so)
    probe_libc:malloc_consolidate__return (on malloc*%return in /usr/lib64/libc-2.25.so)
    probe_libc:malloc_check__return (on malloc*%return in /usr/lib64/libc-2.25.so)
    probe_libc:malloc_hook_ini__return (on malloc*%return in /usr/lib64/libc-2.25.so)
    probe_libc:malloc__return (on malloc*%return in /usr/lib64/libc-2.25.so)
    probe_libc:malloc_trim__return (on malloc*%return in /usr/lib64/libc-2.25.so)
    probe_libc:malloc_usable_size__return (on malloc*%return in /usr/lib64/libc-2.25.so)
    probe_libc:malloc_stats__return (on malloc*%return in /usr/lib64/libc-2.25.so)
    probe_libc:malloc_info__return (on malloc*%return in /usr/lib64/libc-2.25.so)
    probe_libc:mallochook__return (on malloc*%return in /usr/lib64/libc-2.25.so)
    probe_libc:malloc_get_state__return (on malloc*%return in /usr/lib64/libc-2.25.so)
    probe_libc:malloc_set_state__return (on malloc*%return in /usr/lib64/libc-2.25.so)

  You can now use it in all perf tools, such as:

	  perf record -e probe_libc:malloc_set_state__return -aR sleep 1

  =====

Reported-by: Arnaldo Carvalho de Melo <acme@kernel.org>
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Acked-by: Ravi Bangoria <ravi.bangoria@linux.vnet.ibm.com>
Reviewed-by: Thomas Richter <tmricht@linux.vnet.ibm.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Paul Clarke <pc@us.ibm.com>
Cc: bhargavb <bhargavaramudu@gmail.com>
Cc: linux-rt-users@vger.kernel.org
Link: http://lkml.kernel.org/r/151275046418.24652.6696011972866498489.stgit@devbox


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