tools lib traceevent: Fix build failure on 32-bit arch

In my i386 build, it failed like this:

    CC       event-parse.o
  event-parse.c: In function 'print_str_arg':
  event-parse.c:3868:5: warning: format '%lu' expects argument of type 'long unsigned int',
                        but argument 3 has type 'uint64_t' [-Wformat]

Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Acked-by: Javi Merino <javi.merino@arm.com>
Link: http://lkml.kernel.org/r/20150424020218.GF1905@sejong
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/lib/traceevent/event-parse.c

@@ -3865,7 +3865,7 @@ static void print_str_arg(struct trace_seq *s, void *data, int size,
 			} else if (el_size == 4) {
 				trace_seq_printf(s, "%u", *(uint32_t *)num);
 			} else if (el_size == 8) {
-				trace_seq_printf(s, "%lu", *(uint64_t *)num);
+				trace_seq_printf(s, "%"PRIu64, *(uint64_t *)num);
 			} else {
 				trace_seq_printf(s, "BAD SIZE:%d 0x%x",
 						 el_size, *(uint8_t *)num);