staging: r8188eu: remove write support from rtl8188e_EfusePowerSwitch

The rtl8188e_EfusePowerSwitch function has a write parameter that is
set to false by its callers.

Remove the parameter and resulting dead code.

Signed-off-by: Martin Kaiser <martin@kaiser.cx>
Link: https://lore.kernel.org/r/20211107161624.9452-2-martin@kaiser.cx


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