uvesafb: Fix continuation printks without KERN_LEVEL to pr_cont, neatening

Linus recently broke the printk without KERN_CONT behavior.
Fix it for uvesafb.

While there, convert printk(KERN_<LEVEL> to pr_<level>.
Add pr_fmt and remove the embedded prefixes.

Miscellanea:

o Coalesce formats and realign arguments
o Add a missing space to a format when coalescing.
Signed-off-by: Joe Perches <joe@perches.com>
Cc: Michal Januszewski <spock@gentoo.org>
Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>