kmsg: properly support writev to avoid interleaved printk lines fix

make `len' size_t, avoid multiple-assignments.

Cc: Kay Sievers <kay.sievers@vrfy.org>
Cc: Lennart Poettering <lennart@poettering.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

drivers/char/mem.c

@@ -810,18 +810,19 @@ static ssize_t kmsg_writev(struct kiocb *iocb, const struct iovec *iv,
 			   unsigned long count, loff_t pos)
 {
 	char *line, *p;
-	int len, i;
+	int i;
 	ssize_t ret = -EFAULT;
+	size_t len = iov_length(iv, count);
 
-	len = iov_length(iv, count);
-	line = p = kmalloc(len + 1, GFP_KERNEL);
+	line = kmalloc(len + 1, GFP_KERNEL);
 	if (line == NULL)
 		return -ENOMEM;
 
 	/*
 	 * copy all vectors into a single string, to ensure we do
 	 * not interleave our log line with other printk calls
 	 */
+	p = line;
 	for (i = 0; i < count; i++) {
 		if (copy_from_user(p, iv[i].iov_base, iv[i].iov_len))
 			goto out;