perf session: Remove one more exit() call from library code

Return NULL instead and make the caller propagate the error.

LKML-Reference: <new-submission>
Cc: Frédéric Weisbecker <fweisbec@gmail.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
diff --git a/tools/perf/util/session.c b/tools/perf/util/session.c
index 9da5e72..ddf288f 100644
--- a/tools/perf/util/session.c
+++ b/tools/perf/util/session.c
@@ -118,16 +118,11 @@
 						   struct symbol **parent)
 {
 	u8 cpumode = PERF_RECORD_MISC_USER;
-	struct map_symbol *syms = NULL;
 	unsigned int i;
+	struct map_symbol *syms = calloc(chain->nr, sizeof(*syms));
 
-	if (symbol_conf.use_callchain) {
-		syms = calloc(chain->nr, sizeof(*syms));
-		if (!syms) {
-			fprintf(stderr, "Can't allocate memory for symbols\n");
-			exit(-1);
-		}
-	}
+	if (!syms)
+		return NULL;
 
 	for (i = 0; i < chain->nr; i++) {
 		u64 ip = chain->ips[i];