perf: Provide generic perf_sample_data initialization

perf: Provide generic perf_sample_data initialization

This makes it easier to extend perf_sample_data and fixes a bug on arm
and sparc, which failed to set ->raw to NULL, which can cause crashes
when combined with PERF_SAMPLE_RAW.

It also optimizes PowerPC and tracepoint, because the struct
initialization is forced to zero out the whole structure.

Signed-off-by: Peter Zijlstra <[email protected]>
Acked-by: Jean Pihet <[email protected]>
Reviewed-by: Frederic Weisbecker <[email protected]>
Acked-by: David S. Miller <[email protected]>
Cc: Jamie Iles <[email protected]>
Cc: Paul Mackerras <[email protected]>
Cc: Stephane Eranian <[email protected]>
Cc: [email protected]
LKML-Reference: <20100304140100.315416040@chello.nl>
Signed-off-by: Ingo Molnar <[email protected]>