ppdev: Add an error check in register_device

In register_device, the return value of ida_simple_get is unchecked,
in witch ida_simple_get will use an invalid index value.

To address this issue, index should be checked after ida_simple_get. When
the index value is abnormal, a warning message should be printed, the port
should be dropped, and the value should be recorded.

Fixes: 9a69645d

 ("ppdev: fix registering same device name")
Signed-off-by: Huai-Yuan Liu <qq810974084@gmail.com>
Link: https://lore.kernel.org/r/20240412083840.234085-1-qq810974084@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>