staging: r8188eu: remove unused enum RT_SPINLOCK_TYPE

The enum RT_SPINLOCK_TYPE is not used in the driver, remove it.

Signed-off-by: Michael Straube <straube.linux@gmail.com>
Link: https://lore.kernel.org/r/20210913192043.26527-2-straube.linux@gmail.com


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