iotests: 255: Drop blockdev_create()

blockdev_create() is completely unused in this test case, so we can just
drop it.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>

tests/qemu-iotests/255

@@ -25,16 +25,6 @@ from iotests import imgfmt
 
 iotests.verify_image_format(supported_fmts=['qcow2'])
 
-def blockdev_create(vm, options):
-    result = vm.qmp_log('blockdev-create',
-                        filters=[iotests.filter_qmp_testfiles],
-                        job_id='job0', options=options)
-
-    if 'return' in result:
-        assert result['return'] == {}
-        vm.run_job('job0')
-    iotests.log("")
-
 iotests.log('Finishing a commit job with background reads')
 iotests.log('============================================')
 iotests.log('')