kmsg: add the facility number to the syslog prefix

After the recent split of facility and level into separate variables,
we miss the facility value (always 0 for kernel-originated messages)
in the syslog prefix.

On Tue, Jul 3, 2012 at 12:45 PM, Dan Carpenter <dan.carpenter@oracle.com> wrote:
> Static checkers complain about the impossible condition here.
>
> In 084681d1 ('printk: flush continuation lines immediately to
> console'), we changed msg->level from being a u16 to being an unsigned
> 3 bit bitfield.

Cc: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Kay Sievers <kay@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

kernel/printk.c

@@ -818,15 +818,18 @@ static size_t print_time(u64 ts, char *buf)
 static size_t print_prefix(const struct log *msg, bool syslog, char *buf)
 {
 	size_t len = 0;
+	unsigned int prefix = (msg->facility << 3) | msg->level;
 
 	if (syslog) {
 		if (buf) {
-			len += sprintf(buf, "<%u>", msg->level);
+			len += sprintf(buf, "<%u>", prefix);
 		} else {
 			len += 3;
-			if (msg->level > 9)
-				len++;
-			if (msg->level > 99)
+			if (prefix > 999)
+				len += 3;
+			else if (prefix > 99)
+				len += 2;
+			else if (prefix > 9)
 				len++;
 		}
 	}