Don't touch blackfin with printk typo fixes

This is a partial revert of b595076a ("tree-wide: fix comment/printk
typos"), as blackfin tree is going to have completely different
version of the code.

Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>