staging: r8188eu: use bool for boolean values

Change some boolean variables from u8 to bool.

Signed-off-by: Martin Kaiser <martin@kaiser.cx>
Link: https://lore.kernel.org/r/20211226195556.159471-13-martin@kaiser.cx


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