enic: use netdev_<foo> or dev_<foo> instead of pr_<foo>

pr_info does not give any details about the interface involved. This patch
uses netdev_info for printing the message. Use dev_info where netdev is not
ready.

Signed-off-by: Govindarajulu Varadarajan <_govind@gmx.com>
Signed-off-by: David S. Miller <davem@davemloft.net>