[PATCH v2 02/17] iotests/163: Fix broken qemu-io invocation

[John Snow <jsnow@redhat.com>]

The 'read' commands to qemu-io were malformed, and this invocation only
worked by coincidence because the error messages were identical. Oops.

There's no point in checking the patterning of the reference image, so
just check the empty image by itself instead.

(Note: as of this commit, nothing actually enforces that this command
completes successfully, but a forthcoming commit in this series will
enforce that qemu_io() must have a zero status code.)

Signed-off-by: John Snow <jsnow@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Hanna Reitz <hreitz@redhat.com>
---
 tests/qemu-iotests/163 | 5 +----
 1 file changed, 1 insertion(+), 4 deletions(-)

diff --git a/tests/qemu-iotests/163 b/tests/qemu-iotests/163
index e4cd4b230f..c94ad16f4a 100755
--- a/tests/qemu-iotests/163
+++ b/tests/qemu-iotests/163
@@ -113,10 +113,7 @@ class ShrinkBaseClass(iotests.QMPTestCase):
         qemu_img('resize',  '-f', iotests.imgfmt, '--shrink', test_img,
                  self.shrink_size)
 
-        self.assertEqual(
-            qemu_io('-c', 'read -P 0x00 %s'%self.shrink_size, test_img),
-            qemu_io('-c', 'read -P 0x00 %s'%self.shrink_size, check_img),
-            "Verifying image content")
+        qemu_io('-c', f"read -P 0x00 0 {self.shrink_size}", test_img)
 
         self.image_verify()
 
-- 
2.34.1