snapshot/tests: Try loadvm twice

It's legal to loadvm twice, modify the existing save/loadvm test
to do it twice.

Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Message-Id: <20170825141940.20740-3-dgilbert@redhat.com>
Reviewed-by: Peter Xu <peterx@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>

tests/qemu-iotests/068

@@ -78,7 +78,7 @@ for extra_args in \
     # Give qemu some time to boot before saving the VM state
     { sleep 1; printf "savevm 0\nquit\n"; } | _qemu $extra_args
     # Now try to continue from that VM state (this should just work)
-    echo quit | _qemu $extra_args -loadvm 0
+    { sleep 1; printf "loadvm 0\nloadvm 0\nquit\n"; } | _qemu $extra_args -S
 done
 
 # success, all done

tests/qemu-iotests/068.out

@@ -7,6 +7,8 @@ QEMU X.Y.Z monitor - type 'help' for more information
 (qemu) savevm 0
 (qemu) quit
 QEMU X.Y.Z monitor - type 'help' for more information
+(qemu) loadvm 0
+(qemu) loadvm 0
 (qemu) quit
 
 === Saving and reloading a VM state to/from a qcow2 image (-object iothread,id=iothread0 -set device.hba0.iothread=iothread0) ===
@@ -16,5 +18,7 @@ QEMU X.Y.Z monitor - type 'help' for more information
 (qemu) savevm 0
 (qemu) quit
 QEMU X.Y.Z monitor - type 'help' for more information
+(qemu) loadvm 0
+(qemu) loadvm 0
 (qemu) quit
 *** done