block: remove superfluous '\n' around error_report/error_setg

Signed-off-by: Gonglei <arei.gonglei@huawei.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
diff --git a/qemu-img.c b/qemu-img.c
index 7ac7f56..6d17755 100644
--- a/qemu-img.c
+++ b/qemu-img.c
@@ -1645,7 +1645,7 @@
     if (skip_create) {
         int64_t output_sectors = blk_nb_sectors(out_blk);
         if (output_sectors < 0) {
-            error_report("unable to get output image length: %s\n",
+            error_report("unable to get output image length: %s",
                          strerror(-output_sectors));
             ret = -1;
             goto out;