staging: r8188eu: core: remove the goto from rtw_IOL_accquire_xmit_frame

staging: r8188eu: core: remove the goto from rtw_IOL_accquire_xmit_frame

Remove the goto statement from rtw_IOL_accquire_xmit_frame(). In this
function goto can be replace by return statement. As on goto label
exit, function only return it is not performing any cleanup. Avoiding
goto will improve the function readability.

Remove the assignment of NULL to local variable xmit_frame just before
return of function. As function return, local variable will be not
available on memory. So assigning a NULL value to local variable just
before function return does not required.

Signed-off-by: Saurav Girepunje <saurav.girepunje@gmail.com>
Link: https://lore.kernel.org/r/YXd8QdhiNX3B1nqe@Sauravs-MacBook-Air.local
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>