staging: r8188eu: use KBUILD_MODNAME instead of a string constant

staging: r8188eu: use KBUILD_MODNAME instead of a string constant

The field .usbdrv.name of the struct rtw_usb_drv hardcoded the module
(driver) name as a constant string. Replace the string with the
KBUILD_MODNAME macro.

Link: https://lore.kernel.org/lkml/Yuy7QSh%2FclQ5Ki09@kroah.com/
Suggested-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Tested-by: Philipp Hortmann <philipp.g.hortmann@gmail.com> # Edimax N150
Signed-off-by: Grzegorz Szymaszek <gszymaszek@short.pl>
Link: https://lore.kernel.org/r/0325540ba8be0a3dc4083d22e484a8a31fb2a892.1659715931.git.gszymaszek@short.pl
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>