USB: keyspan: pull in one indent level

We can remove the "if (urb->actual_length) {" check because checking for
"while (i < urb->actual_length) {" is sufficient.  This lets us pull the
code in one indent level.

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>