staging: vt6655: Use loop in vt6655_mac_read_ether_addr

Use loop in vt6655_mac_read_ether_addr to avoid multiple
similar statements.

Signed-off-by: Philipp Hortmann <philipp.g.hortmann@gmail.com>
Link: https://lore.kernel.org/r/f233c8a007d75a8adcc99a07c582b75bdc1985db.1657134099.git.philipp.g.hortmann@gmail.com


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