staging: r8188eu: RfRegChnlVal[1] is set but not used

RfRegChnlVal[1] in hal_data_8188e is set but not used. This driver needs
only one RfRegChnlVal setting. Replace the array with a single u32.

Signed-off-by: Martin Kaiser <martin@kaiser.cx>
Link: https://lore.kernel.org/r/20220205113741.379070-7-martin@kaiser.cx


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