Fix warning typo "CONFIG_RELCOATABLE"

Fix typo "CONFIG_RELCOATABLE" in a warning message. While we're at it,
also make that warning an actual sentence and fix comparable typos in
some comments.

Signed-off-by: Paul Bolle <pebolle@tiscali.nl>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>