iotests: Use _img_info in test 089

Currently, test 089 uses $QEMU_IMG info manually in order to obtain the
according output. However, the iotests should generally use _img_info as
this filters out more irrelevant information such as the host image size
or format specific information. Therefore, test 089 should use _img_info
as well.

Signed-off-by: Max Reitz <mreitz@redhat.com>
Reported-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>

tests/qemu-iotests/089

@@ -107,8 +107,7 @@ echo
 echo "=== Testing qemu-img info output ==="
 echo
 
-$QEMU_IMG info "json:{\"driver\":\"qcow2\",\"file.filename\":\"$TEST_IMG\"}" \
-    | _filter_testdir | _filter_imgfmt
+TEST_IMG="json:{\"driver\":\"qcow2\",\"file.filename\":\"$TEST_IMG\"}" _img_info
 
 
 echo

tests/qemu-iotests/089.out

@@ -31,11 +31,7 @@ read failed: Input/output error
 image: TEST_DIR/t.IMGFMT
 file format: IMGFMT
 virtual size: 64M (67108864 bytes)
-disk size: 324K
 cluster_size: 65536
-Format specific information:
-    compat: 1.1
-    lazy refcounts: false
 
 === Testing option merging ===