i2c: Hide probe errors caused by ACPI resource conflicts

When an ACPI resource conflict is detected, error messages are already
printed by ACPI. There's no point in causing the driver core to print
more error messages, so return one of the error codes for which no
message is printed.

This fixes bug #14293:
http://bugzilla.kernel.org/show_bug.cgi?id=14293



Signed-off-by: Jean Delvare <khali@linux-fr.org>