i2c-dev: Return correct error code on class_create() failure

We need to convert the error pointer from class_create(), else we'll return the
successful return code from register_chrdev() on failure.

Signed-off-by: Sven Wegener <sven.wegener@stealer.net>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
1 file changed