staging: r8188eu: convert DBG_88E_LEVEL call in core/rtw_xmit.c

Convert single DBG_88E_LEVEL macro call in core/rtw_xmit.c to plain
netdev_dbg call, as although the information is potentially useful,
we should be exposing it using standard kernel debugging functionality.

Signed-off-by: Phillip Potter <phil@philpotter.co.uk>
Link: https://lore.kernel.org/r/20211129002041.865-4-phil@philpotter.co.uk


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>