hwmon/lm87: Disable VID when it should be

A stupid bit shifting bug caused the VID value to be always exported
even when the hardware is configured for something different.

Signed-off-by: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Mark M. Hoffman <mhoffman@lightlink.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: Adrian Bunk <bunk@kernel.org>