perf trace: Separate tp syscall field caching into init routine to be reused

We need to set this in evsels coming out of a perf.data file header, not
just for new ones created for live sessions.

So separate the code that caches the syscall entry/exit tracepoint
format fields into a new function that will be used in the next
changeset.

Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/r/20131112115700.GC4053@ghostprotocols.net
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/builtin-trace.c

@@ -149,20 +149,32 @@ static void perf_evsel__delete_priv(struct perf_evsel *evsel)
 	perf_evsel__delete(evsel);
 }
 
+static int perf_evsel__init_syscall_tp(struct perf_evsel *evsel, void *handler)
+{
+	evsel->priv = malloc(sizeof(struct syscall_tp));
+	if (evsel->priv != NULL) {
+		if (perf_evsel__init_sc_tp_uint_field(evsel, id))
+			goto out_delete;
+
+		evsel->handler = handler;
+		return 0;
+	}
+
+	return -ENOMEM;
+
+out_delete:
+	free(evsel->priv);
+	evsel->priv = NULL;
+	return -ENOENT;
+}
+
 static struct perf_evsel *perf_evsel__syscall_newtp(const char *direction, void *handler)
 {
 	struct perf_evsel *evsel = perf_evsel__newtp("raw_syscalls", direction);
 
 	if (evsel) {
-		evsel->priv = malloc(sizeof(struct syscall_tp));
-
-		if (evsel->priv == NULL)
+		if (perf_evsel__init_syscall_tp(evsel, handler))
 			goto out_delete;
-
-		if (perf_evsel__init_sc_tp_uint_field(evsel, id))
-			goto out_delete;
-
-		evsel->handler = handler;
 	}
 
 	return evsel;