perf bench numa: Fix type of loop iterator in do_work, it should be 'long'

'j' is of type int and start/end are of type 'long'. Thus 'j' might become
negative and cause segfault in access_data(). Fix it by using 'long' for
'j' as well.
Reviewed-by: James Clark <james.clark@arm.com>
Signed-off-by: Andreas Herrmann <aherrmann@suse.de>
Link: https://lore.kernel.org/r/20230330074202.14052-1-aherrmann@suse.deSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/bench/numa.c

@@ -847,7 +847,7 @@ static u64 do_work(u8 *__data, long bytes, int nr, int nr_max, int loop, u64 val
 
 	if (g->p.data_rand_walk) {
 		u32 lfsr = nr + loop + val;
-		int j;
+		long j;
 
 		for (i = 0; i < words/1024; i++) {
 			long start, end;