media: uvcvideo: Fix spelling mistake: "entites" -> "entities"

Trivial fix to spelling mistake in uvc_printk message

[Unwrap message string, remove unneeded curly braces]

Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>