qmp: add and use q type specifier

"O" is being used by the transaction and qom-set commands to mean "any
QObject", but it really means "do not validate the argument list".
Add a new specifier with the correct meaning.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Anthony Liguori <aliguori@us.ibm.com>
Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>

monitor.c

@@ -4157,6 +4157,9 @@ static int check_client_args_type(const QDict *client_args,
         case 'O':
             assert(flags & QMP_ACCEPT_UNKNOWNS);
             break;
+        case 'q':
+            /* Any QObject can be passed.  */
+            break;
         case '/':
         case '.':
             /*

qmp-commands.hx

@@ -708,7 +708,7 @@ EQMP
     },
     {
         .name       = "transaction",
-        .args_type  = "actions:O",
+        .args_type  = "actions:q",
         .mhandler.cmd_new = qmp_marshal_input_transaction,
     },
 
@@ -2125,7 +2125,7 @@ EQMP
 
     {
         .name       = "qom-set",
-	.args_type  = "path:s,property:s,opts:O",
+	.args_type  = "path:s,property:s,value:q",
 	.mhandler.cmd_new = qmp_qom_set,
     },