Staging: comedi: das1800.c: fix a locking error on the error path.

Cc: Ian Abbott <abbotti@mev.co.uk>
Cc: Frank Mori Hess <fmhess@users.sourceforge.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

drivers/staging/comedi/drivers/das1800.c

@@ -1637,14 +1637,16 @@ static int das1800_ai_rinsn(struct comedi_device *dev,
 		}
 		if (i == timeout) {
 			comedi_error(dev, "timeout");
-			return -ETIME;
+			n = -ETIME;
+			goto exit;
 		}
 		dpnt = inw(dev->iobase + DAS1800_FIFO);
 		/* shift data to offset binary for bipolar ranges */
 		if ((conv_flags & UB) == 0)
 			dpnt += 1 << (thisboard->resolution - 1);
 		data[n] = dpnt;
 	}
+exit:
 	spin_unlock_irqrestore(&dev->spinlock, irq_flags);
 
 	return n;