Currently we print expander PHY indexes in a mix of decimal and hex.

It is more consistent and also more convenient to read decimal, so
make this change.

We use width of 2 for expander and 1 for root PHYs prints.

Some lines which were needlessly spilling multiple lines are unified.
Signed-off-by: John Garry <john.garry@huawei.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>