usb: langwell_udc: fix big file transfer issue.

This patch fixing the problem with large file transfers failing. Swap the read
order to avoid unexpected RX status.

Signed-off-by: Christophe Lebouc <christophex.lebouc@intel.com>
Signed-off-by: Hao Wu <hao.wu@intel.com>
Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>