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 <[email protected]>
Signed-off-by: David S. Miller <[email protected]>
6 files changed