enic: Use (netdev|dev|pr)_<level> macro helpers for logging

Replace all printk routines with the (netdev|dev|pr)_<level> macros that
provide verbose logs.

Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Scott Feldman <scofeldm@cisco.com>
Signed-off-by: Vasanthy Kolluri <vkolluri@cisco.com>
Signed-off-by: Roopa Prabhu <roprabhu@cisco.com>
Signed-off-by: David S. Miller <davem@davemloft.net>