um: vector: Clean up and modernize log messages

Use pr_*() and netdev_*() to print log messages. While at it,
join split messages for easier grepping.

Suggested-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Tiwei Bie <tiwei.btw@antgroup.com>
Link: https://patch.msgid.link/20250506045117.1896661-2-tiwei.btw@antgroup.com


Signed-off-by: Johannes Berg <johannes.berg@intel.com>