sunhme: Combine continued messages

This driver seems to have been written under the assumption that messages
can be continued arbitrarily. I'm not when this changed (if ever), but such
ad-hoc continuations are liable to be rudely interrupted. Convert all such
instances to single prints. This loses a bit of timing information (such as
when a line was constructed piecemeal as the function executed), but it's
easy to add a few prints if necessary. This also adds newlines to the ends
of any prints without them.

Since (almost every) debug print included the name of the function, include
it automatically.

Signed-off-by: Sean Anderson <seanga2@gmail.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>