drivers/isdn/mISDN: Use printf extension %pV

Using %pV reduces the number of printk calls and
eliminates any possible message interleaving from
other printk calls.

Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/isdn/mISDN/layer1.c b/drivers/isdn/mISDN/layer1.c
index ac4aa18..5cc7c00 100644
--- a/drivers/isdn/mISDN/layer1.c
+++ b/drivers/isdn/mISDN/layer1.c
@@ -99,12 +99,16 @@
 l1m_debug(struct FsmInst *fi, char *fmt, ...)
 {
 	struct layer1 *l1 = fi->userdata;
+	struct va_format vaf;
 	va_list va;
 
 	va_start(va, fmt);
-	printk(KERN_DEBUG "%s: ", dev_name(&l1->dch->dev.dev));
-	vprintk(fmt, va);
-	printk("\n");
+
+	vaf.fmt = fmt;
+	vaf.va = &va;
+
+	printk(KERN_DEBUG "%s: %pV\n", dev_name(&l1->dch->dev.dev), &vaf);
+
 	va_end(va);
 }