staging: r8188eu: remove HW_VAR_CAM_EMPTY_ENTRY

The HW_VAR_CAM_EMPTY_ENTRY case in SetHwReg8188EU() is not used.
Remove it.

Signed-off-by: Michael Straube <straube.linux@gmail.com>
Link: https://lore.kernel.org/r/20220130190321.7172-13-straube.linux@gmail.com


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