mISDN: comment out unused symbols

Fix this sparse warnings:

  drivers/isdn/hardware/mISDN/hfcmulti.c:794: warning: 'vpm_check' defined but not used
  drivers/isdn/mISDN/dsp_cmx.c:1546: warning: 'dsp_start_jiffies' defined but not used

Signed-off-by: Hannes Eder <hannes@hanneseder.net>
Acked-by: Karsten Keil <kkeil@suse.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/isdn/hardware/mISDN/hfcmulti.c b/drivers/isdn/hardware/mISDN/hfcmulti.c
index 970201d..0668072 100644
--- a/drivers/isdn/hardware/mISDN/hfcmulti.c
+++ b/drivers/isdn/hardware/mISDN/hfcmulti.c
@@ -788,6 +788,7 @@
 	}
 }
 
+#ifdef UNUSED
 static void
 vpm_check(struct hfc_multi *hctmp)
 {
@@ -798,6 +799,7 @@
 	if ((gpi2 & 0x3) != 0x3)
 		printk(KERN_DEBUG "Got interrupt 0x%x from VPM!\n", gpi2);
 }
+#endif /* UNUSED */
 
 
 /*