This reverts commit 543e3a8da5a4c453e992d5351ef405d5e32f27d7.
Direct callers of __netpoll_setup() depend on it to set np->dev,
so we can't simply move that assignment up to netpoll_stup().
Reported-by: Bart Van Assche <bart.vanassche@xxxxxxxxxxx>
Signed-off-by: Bjorn Helgaas <bhelgaas@xxxxxxxxxx>