dfu: newline after updating

Currently output of dfu commands ends on a line with leading hash signs
('#'). The succeeding output should be placed on a new line.

After writing updates via dfu print a new line.

Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
Signed-off-by: Heinrich Schuchardt <heinrich.schuchardt@canonical.com>
diff --git a/drivers/dfu/dfu.c b/drivers/dfu/dfu.c
index ff1859d..af39759 100644
--- a/drivers/dfu/dfu.c
+++ b/drivers/dfu/dfu.c
@@ -735,6 +735,7 @@
 	ret = dfu_flush(dfu, NULL, 0, i);
 	if (ret)
 		pr_err("DFU flush failed!");
+	puts("\n");
 
 	return ret;
 }