staging: comedi: Fix reversed test in comedi_device_attach()

Commit 3902a370 (staging: comedi:
refactor comedi_device_attach() a bit) by yours truly introduced an
inverted logic bug in comedi_device_attach() for the case where the
driver expects the device to be configured by driver name rather than
board name.  The result of a strcmp() is being tested incorrectly.  Fix
it.

Thanks to Stephen N Chivers for discovering the bug and suggesting the
fix.

Cc: <stable@vger.kernel.org> # 3.5.x
Signed-off-by: NIan Abbott <abbotti@mev.co.uk>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/comedi/drivers.c

@@ -168,7 +168,7 @@ int comedi_device_attach(struct comedi_device *dev, struct comedi_devconfig *it)
 			dev->board_ptr = comedi_recognize(driv, it->board_name);
 			if (dev->board_ptr)
 				break;
-		} else if (strcmp(driv->driver_name, it->board_name))
+		} else if (strcmp(driv->driver_name, it->board_name) == 0)
 			break;
 		module_put(driv->module);
 	}