Added option to display dump/restore lazy and zero pages stats

 # criu dump --display-stats -D /tmp/cp -t <PID>
 Displaying dump stats:
 ...
 Zero memory pages: 0 (0x0)
 Lazy memory pages: 0 (0x0)

travis-ci: success for Added option to display dump/restore stats (rev2)
Signed-off-by: Adrian Reber <areber@redhat.com>
Signed-off-by: Pavel Emelyanov <xemul@virtuozzo.com>

criu/stats.c

@@ -120,6 +120,10 @@ static void display_stats(int what, StatsEntry *stats)
 				stats->dump->pages_skipped_parent);
 		pr_msg("Memory pages written: %" PRIu64 " (0x%" PRIx64 ")\n", stats->dump->pages_written,
 				stats->dump->pages_written);
+		pr_msg("Zero memory pages: %" PRIu64 " (0x%" PRIx64 ")\n", stats->dump->pages_zero,
+				stats->dump->pages_zero);
+		pr_msg("Lazy memory pages: %" PRIu64 " (0x%" PRIx64 ")\n", stats->dump->pages_lazy,
+				stats->dump->pages_lazy);
 	} else if (what == RESTORE_STATS) {
 		pr_msg("Displaying restore stats:\n");
 		pr_msg("Pages compared: %" PRIu64 " (0x%" PRIx64 ")\n", stats->restore->pages_compared,