qemu-iotests: Fix 051 reference output

Commit 684b2544 forgot to update it.
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

tests/qemu-iotests/051.out

@@ -24,7 +24,7 @@ QEMU X.Y.Z monitor - type 'help' for more information
 (qemu) iininfinfoinfo info binfo blinfo bloinfo blocinfo block
 ide0-hd0: TEST_DIR/t.qcow2 (qcow2)
     Backing file:     TEST_DIR/t.qcow2.orig (chain depth: 1)
- [not inserted](qemu) qququiquit
+(qemu) qququiquit
 
 
 === Enable and disable lazy refcounting on the command line, plus some invalid values ===