perf session: Reduce the number of parms to perf_session__process_events

perf session: Reduce the number of parms to perf_session__process_events

By having the cwd/cwdlen in the perf_session struct and
full_paths in perf_event_ops.

Now its just a matter of passing the ops.

Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
Cc: Frédéric Weisbecker <[email protected]>
Cc: Mike Galbraith <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Paul Mackerras <[email protected]>
LKML-Reference: <1260741029[email protected]>
Signed-off-by: Ingo Molnar <[email protected]>