tools: kwboot: Fix printing progress

Ensure that `pos` is still in range up to the `width` so printing 100%
works also for bigger images. After printing 100% progress reset it to
zero, so that next progressbar can be started.

Signed-off-by: Pali Rohár <pali@kernel.org>
Reviewed-by: Marek Behún <marek.behun@nic.cz>
Reviewed-by: Stefan Roese <sr@denx.de>
diff --git a/tools/kwboot.c b/tools/kwboot.c
index 3d9f73e..eb4b3fe 100644
--- a/tools/kwboot.c
+++ b/tools/kwboot.c
@@ -140,12 +140,14 @@
 	fputc(c, stdout);
 
 	nl = "]\n";
-	pos++;
+	pos = (pos + 1) % width;
 
 	if (pct == 100) {
-		while (pos++ < width)
+		while (pos && pos++ < width)
 			fputc(' ', stdout);
 		fputs(nl, stdout);
+		nl = "";
+		pos = 0;
 	}
 
 	fflush(stdout);
@@ -162,6 +164,9 @@
 
 	if (kwboot_verbose)
 		__progress(pct, c);
+
+	if (pct == 100)
+		pct = 0;
 }
 
 static int