net: core: Use pr_<level>

Use the current logging style.

This enables use of dynamic debugging as well.

Convert printk(KERN_<LEVEL> to pr_<level>.
Add pr_fmt. Remove embedded prefixes, use
%s, __func__ instead.

Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --cc net/core/drop_monitor.c
Simple merge

diff --cc net/core/neighbour.c
Simple merge

diff --cc net/core/net_namespace.c
Simple merge

diff --cc net/core/netprio_cgroup.c
Simple merge

diff --cc net/core/skbuff.c
Simple merge

diff --cc net/core/sock.c
Simple merge