perf sched: Fix list of events, dropping unsupported ':r' modifier

Looks to me like the :r modifier is not supported anymore, so remove it from
the list of events.

Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Robert Richter <robert.richter@amd.com>
LKML-Reference: <AANLkTim=jawJyBj0iFd0r4-LCKzvjFW+NddzJMD5GUB9@mail.gmail.com>
Signed-off-by: Stephane Eranian <eranian@google.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>