Use unsigned printf/scanf conversion where more appropriate

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
diff --git a/networking/pscan.c b/networking/pscan.c
index 28005ad..72ed8cd 100644
--- a/networking/pscan.c
+++ b/networking/pscan.c
@@ -157,7 +157,7 @@
 	}
 	if (ENABLE_FEATURE_CLEAN_UP) free(lsap);
 
-	printf("%d closed, %d open, %d timed out (or blocked) ports\n",
+	printf("%u closed, %u open, %u timed out (or blocked) ports\n",
 					closed_ports,
 					open_ports,
 					nports - (closed_ports + open_ports));