iotests: 050: Use TEST_IMG override instead of "mv"

Signed-off-by: NFam Zheng <famz@redhat.com>
Reviewed-by: NMax Reitz <mreitz@redhat.com>
Message-id: 1450752561-9300-10-git-send-email-famz@redhat.com
Signed-off-by: NMax Reitz <mreitz@redhat.com>

tests/qemu-iotests/050

@@ -51,14 +51,19 @@ fi
 echo
 echo "== Creating images =="
 
+TEST_IMG_SAVE="$TEST_IMG"
+TEST_IMG="$TEST_IMG.old"
+
 size=10M
 _make_test_img $size
 $QEMU_IO -c "write -P 0x40 0 1048576" "$TEST_IMG" | _filter_qemu_io
-mv "$TEST_IMG" "$TEST_IMG.old"
+
+TEST_IMG="$TEST_IMG_SAVE.new"
 
 _make_test_img $size
 $QEMU_IO -c "write -P 0x5a 0 1048576" "$TEST_IMG" | _filter_qemu_io
-mv "$TEST_IMG" "$TEST_IMG.new"
+
+TEST_IMG="$TEST_IMG_SAVE"
 
 _make_test_img -b "$TEST_IMG.old" $size
 $QEMU_IO -c "write -z 0 1048576" "$TEST_IMG" | _filter_qemu_io

tests/qemu-iotests/050.out

 QA output created by 050
 
 == Creating images ==
-Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=10485760
+Formatting 'TEST_DIR/t.IMGFMT.old', fmt=IMGFMT size=10485760
 wrote 1048576/1048576 bytes at offset 0
 1 MiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
-Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=10485760
+Formatting 'TEST_DIR/t.IMGFMT.new', fmt=IMGFMT size=10485760
 wrote 1048576/1048576 bytes at offset 0
 1 MiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=10485760 backing_file=TEST_DIR/t.IMGFMT.old