printk: add KERN_CONT annotation

printk: add the KERN_CONT annotation (which is empty string but via
which checkpatch.pl can notice that the lacking KERN_ level is fine).
This useful for multiple calls of hand-crafted printk output done by
early debug code or similar.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Cc: Andy Whitcroft <apw@shadowen.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

include/linux/kernel.h

@@ -76,6 +76,13 @@ extern const char linux_proc_banner[];
 #define	KERN_INFO	"<6>"	/* informational			*/
 #define	KERN_DEBUG	"<7>"	/* debug-level messages			*/
 
+/*
+ * Annotation for a "continued" line of log printout (only done after a
+ * line that had no enclosing \n). Only to be used by core/arch code
+ * during early bootup (a continued line is not SMP-safe otherwise).
+ */
+#define	KERN_CONT	""
+
 extern int console_printk[];
 
 #define console_loglevel (console_printk[0])