perf cpu_map: Align cpu map synthesized events properly.

The size of the resulting cpu map can be smaller than a multiple of
sizeof(u64), resulting in SIGBUS on cpus like Sparc as the next event
will not be aligned properly.

Signed-off-by: David S. Miller <davem@davemloft.net>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kan Liang <kan.liang@intel.com>
Fixes: 6c872901af07 ("perf cpu_map: Add cpu_map event synthesize function")
Link: http://lkml.kernel.org/r/20181011.224655.716771175766946817.davem@davemloft.net
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
diff --git a/tools/perf/util/event.c b/tools/perf/util/event.c
index 0cd4215..0988eb3 100644
--- a/tools/perf/util/event.c
+++ b/tools/perf/util/event.c
@@ -1081,6 +1081,7 @@
 	}
 
 	*size += sizeof(struct cpu_map_data);
+	*size = PERF_ALIGN(*size, sizeof(u64));
 	return zalloc(*size);
 }