staging: comedi: dt3000: Reformat multiple line dereference

Reformat multiple line dereferences for &cmd->scan_begin_arg. Problem
detected by checkpatch.
Signed-off-by: Deepak R Varma <mh12gx2825@gmail.com>
Link: https://lore.kernel.org/r/20200314135852.GA6336@deeUbuntuSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/comedi/drivers/dt3000.c

@@ -439,9 +439,8 @@ static int dt3k_ai_cmdtest(struct comedi_device *dev,
 
 		if (cmd->scan_begin_src == TRIG_TIMER) {
 			arg = cmd->convert_arg * cmd->scan_end_arg;
-			err |= comedi_check_trigger_arg_min(&cmd->
-							    scan_begin_arg,
-							    arg);
+			err |= comedi_check_trigger_arg_min(
+				&cmd->scan_begin_arg, arg);
 		}
 	}