staging: r8188eu: rename some macros to upper case

Rename some macros to upper case to avoid camel case and improve
readability. While at it, remove some unused macros.

Signed-off-by: Michael Straube <straube.linux@gmail.com>
Link: https://lore.kernel.org/r/20220329202141.7028-4-straube.linux@gmail.com


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