powerpc/BSR: cleanup the error path of bsr_init

powerpc/BSR: cleanup the error path of bsr_init

class_create if succeeded returns a pointer to the struct class,
and if it fails, it returns a value enclosed by the pointer, which
can be read by using PTR_ERR.

Handle the error and return it.

result is for error checking of the alloc_chrdev_region, instead
ret can be used, and also if the alloc_chrdev_region fail,
we are still returning -ENODEV, use ret and the error path will
take care of returning of the ret.

Signed-off-by: Devendra Naga <develkernel412222@gmail.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>