If allocating 'pdata_urb' fails, the function will return -ENOMEM
without freeing the memory allocated, just a few lines above, for
'purb' and will leak that memory when 'purb' goes out of scope.

This patch resolves the leak by freeing the allocated storage with
usb_free_urb() before the return.
Signed-off-by: Jesper Juhl <jj@chaosbits.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>