staging: r8188eu: use memcpy for fallback mac address

Use memcpy to store the fallback mac address in eeprom->mac_addr. Do not
copy byte by byte.

Signed-off-by: Martin Kaiser <martin@kaiser.cx>
Link: https://lore.kernel.org/r/20220709171000.180481-8-martin@kaiser.cx


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